Some Christians cringe when they hear the word “evolution,” and not without reason: considering evolution as God’s means of creating the life we see around us suggests that we need to revisit some familiar biblical passages and brings up some tough theological questions. Meanwhile, militant atheists repeatedly invoke evolution in the media, trying to discredit Scripture and the Christian faith. So why focus on such a controversial topic? We at BioLogos understand that these issues can be difficult, but we believe the church is called to consider evolutionary creation. For us, this conversation is not just about abstract ideas and academic debates, but about God’s ongoing creation, the faith of individual believers, and the mission of the church.¹ Here are several points to consider about evolution in light of Christian faith.

Considering evolution helps us understand God's creation

See “Can science and scripture be reconciled?”

As Christians, we believe that “In the beginning, God created the heavens and the earth” (Genesis 1:1), and that the Bible teaches that God reveals himself to us in the natural world he created (“The heavens declare the glory of God”, Psalm 19:1). In the study of God’s creation, scientists have discovered tremendous wonders that reach far beyond what the Bible describes—things like quarks, neurons, and galaxies. Scientists have also discovered abundant evidence of the long history of the universe and of life (including people), which you can read elsewhere on this site. It is crucial that Christians consider this evidence because it comes from God’s own handiwork in the natural world. Since we believe that nature declares God’s glory, we cannot stop listening to the created order when it declares something that seems new to us.

See the category of questions on God’s action in the natural world

At BioLogos, we view evolutionary creation as a description of how and when God brought about all the creatures on earth. We do not see God as distant from this process, for God did not just set up the universe at the beginning and let it go. Instead, he upholds the universe moment by moment, sustaining all things by the power of his word. The regular patterns in nature that we call natural laws have their foundation in the regular, faithful governance of God (see Jeremiah 33:19-26). Thus we believe that God created every species and did it in such a way that we can describe the creation process scientifically. The scientific model of evolution does not replace God as creator any more than the law of gravity replaces God as ruler of the planets.

Considering evolution helps us understand the Creator God

A short video of beautiful places on earth that declare “Our God is an Awesome God”

The created order—nature—also teaches us about the Creator. The heavens declare the glory of God (Psalm 19:1) and show his eternal power and divine nature (Romans 1:20). The Bible is our primary source of knowledge about God, and God’s character cannot be derived by looking at nature alone. But for those who know and trust God as their savior, the created order has the stamp of the Creator all over it.² The starry heavens show God’s glory (Psalm 19), the thunderstorm displays God’s power (Psalm 29), and ecosystems show God’s care for plants and animals (Psalm 104:10-18). Today we know much more about God’s creation than the Biblical authors knew; telescopes and microscopes have expanded our horizons to the very large and the very small. Through science, we’ve learned how things work and fit together, too. Joining study and worship, we can think God’s thoughts after him, tracing his hand through the physical laws he used to create our world, marveling at the way he provides for creation as much as at the endless forms most beautiful he has created.³

Here are three examples of biblical attributes of God emphasized by studying evolutionary science:

• God is extravagant. God did not create just one type of flower, but uses the system of evolution to create a huge variety of flowers, of every size, shape, color, and scent. As opposed to being “wasteful,” a biblical view of evolution helps us appreciate it as a pointer to the extravagance of God’s loving gift of life to the whole earth. God’s creation does not reflect a cold efficiency, but the transformation of such “waste” into worship, just as Jesus honored the woman who poured expensive perfume on his feet⁴ (Mark 14:3-9, John 12:3-8).
• God is patient, and most often works gradually rather than instantaneously. In the natural world, we see God creating life over billions of years, not instantly, and grand geological processes playing out slowly over time, as well. Similarly, in the Bible we read of the centuries that passed between God’s covenant with Abraham and his covenant with David and the centuries more before Jesus appeared “in the fullness of time” (Galatians 4:4). In individual lives, God often works by planting his Word deep in us and letting it grow slowly over time. God seems pleased with the slow but extraordinary unfolding of his universe, just as he is patiently unfolding his plan of redemption.⁵
• God is the provider. He provides for his creatures in each moment, giving them what they need to survive, adapt and thrive in communities of life. The Bible speaks of God feeding and caring for animals (Jonah 4:11, Psalm 104), and modern evolutionary science is shedding light on how God has arranged complex ecosystems that support many different kinds of creatures together. But God provides for his creatures even at the genetic level, giving species a measure of biological “creativity” to help them respond to new challenges. As biologist Richard Colling says, “Evolution is not about the imposition of death and destruction and survival of the fittest. Those things are a part of it, but not the main core of what evolution is. . . [The] evolutionary process of creating duplicate genes that give rise to new possibilities [is] redemption, it’s possibility, and it’s hope.”⁶

Considering evolution helps the Church confront atheist worldviews

Considering evolution provides an opportunity to challenge atheistic arguments, rather than supporting them. Evolution is not rightly a philosophy or worldview: it is a scientific model that describes the patterns and rules we see in God’s creation of life—much as gravity describes the interaction he has ordained or planets and stars, or as quantum mechanics describes the relationships between elementary particles of matter. By reasserting that evolution is a description of God’s processes and not a worldview in and of itself, Christians can help show atheism to be secular philosophy and not part of science.

Ian Hutchinson, MIT professor of nuclear engineering, is one believing scientist responding to atheist arguments (video and blog)

Similarly, we should reject claims that evolution has effectively disproved the existence of God, debunked Christianity, and shown that faith is based on nothing more than superstition, clearly and forcefully refuting such claims in public. But to be effective in that task, our response should not be to attack what science shows so compellingly about the created order, but again, to expose these atheist arguments as philosophy, rather than science. Scientific explanations of natural process do not eliminate God or deny his sovereignty over creation, and science cannot prove or disprove the existence of God. But exploring creation with the tools of science can profoundly enhance and support belief in and worship of God, a case that Christian philosophers have been convincingly making in the public square.⁷

Considering evolution helps Christian students to remain strong in their faith

How should Christians respond to atheist philosophy in the guise of science? Just as Lois and Eunice raised Timothy in the faith (2 Tim 1:5, 3:14-15), so do all Christian parents, pastors, and teachers want to prepare young people to keep their faith strong as they enter university and adult careers. But while it’s wise to arm young believers against atheistic worldviews, teaching them to ignore the science can unwittingly set young people up for a crisis of faith.⁸ When Christian students encounter the powerful scientific evidence for evolution, many realize their parents and pastors may have been wrong about science and begin to question other beliefs they were taught. One recent survey shows that a key factor in the evangelical Church losing its credibility among young people is its hostility towards mainstream science and its assertion of young-earth and anti-evolutionary creation models that contradict virtually all of the evidence God is revealing through science.⁹

On the other hand, another recent study has shown that biology professors who follow Jesus and accept evolution offer a powerful counter-narrative to those who equate evolution with atheism and can help students find their way forward in faith and prepare them to carry their witness into the wider scientific culture. If parents and church leaders also emphasized the centrality of Jesus and the gospel and taught that Bible-believing Christians hold an array of views with respect to how God created life, young people would be better equipped to reject atheistic worldviews and inspired to explore God’s creation more deeply.

Considering evolution aids evangelism among scientists

Understanding evolution can aid evangelism to those who work in science and technology fields, whereas anti-evolution and anti-science attitudes in the church can hinder evangelism to scientists. While atheism among scientists is actually less common than the popular stereotype,¹⁰ a recent study indicated that over 80% of top scientists do not attend worship services regularly and likely do not know Jesus as their Savior, while another found that many top research scientists who had left the faith did so because the church wasn’t welcoming to them or their questions.¹¹ Because some Christians claim that evolution must be rejected in order to convert to Christianity or remain a faithful follower of Christ, the Church may become a stumbling block to faith rather that a place to nurture those who are seeking God. Indeed, this argument adds an unbiblical requirement for joining the Body of Christ, much as some in the early church wanted to add the requirement of circumcision for gentiles coming to Christ (Acts 15).

Meet some top scientists who are Christians, from the past and the present (blog)

On the contrary, the Church’s support of scientists both inside and outside the church advances the Kingdom. One of the most powerful responses to academic atheism occurs when believing scientists pray for and care for their non-Christian colleagues¹² (Matthew 5:43-48), and atheistic or agnostic scientists are more likely to listen to the good news from a fellow scientist they know and respect. The small percentage of scientists who are evangelical believers need the prayers and support of their brothers and sister in Christ to effectively share their faith with their co-workers. Furthermore, Churches—especially those near universities and high-tech industries—can strengthen their missions outreach and edify their congregations by actively inviting scientists, technicians, and engineers from their communities to church. Learning about the daily lives of scientists¹³ in this way not only shows hospitality and the love of Christ to an “unreached people,” it helps congregations cultivate their own sense of wonder and curiosity about the God’s creation.¹⁴

Considering evolution helps the church engage culture

Os Guinness explains why the church has nothing to fear when considering science. (blog)

Because today’s culture is saturated with science and technology—from the latest communication gadgets to new medical imaging methods to discoveries of fundamental particles and biotechnology—engaging culture means engaging science. Christians should be a compelling and relevant voice on science issues in the public square—especially in discerning appropriate use of new technologies. Many such innovations touch on our understanding of the processes and interrelation of life on earth described by evolutionary science. Especially in the field of bioethics, Christian voices are critical to rightly discerning questions about the development of stem cells, the use of DNA information, and care for the aged and disabled.

But to be compelling and relevant, Christians need to be well-informed. When Christians speak from ignorance about scientific research, we harm the reputation of the whole church and invite mockery. This was an issue even in the days of Saint Augustine (354-386 A.D.), who wrote, “It is a disgraceful and dangerous thing for an unbeliever to hear a Christian, presumably giving the meaning of Holy Scripture, talking nonsense . . . in a field [the unbeliever] himself knows well.” Today, evangelical Christians can show that we love God’s work in the created order, take up full participation in cutting-edge research, and advocate science as a tool to protect rather than prey upon the helpless (Proverbs 6:16-17).

Why should Christians consider evolutionary creation? Because we recognize that nature is God’s creation, declaring the glory, extravagance, and loving care of the Creator; because rightly understanding evolution helps us to refute atheist worldviews and support the faith of those called to explore creation through the sciences; and because it strengthens the voice of Church in the public square.

The Cambrian Explosion is often posed as a challenge for evolution because the sudden burst of change in the fossil record appears to be inconsistent with the more typical gradual pace of evolutionary change. However, although different in certain ways, there are other times of very rapid evolutionary change recorded in the fossil record -- often following times of major extinction. The Cambrian Explosion does present a number of challenging and important questions because it represents the time during which the main branches of the animal tree of life became established. It does not create a challenge to the fundamental correctness of the central thesis of evolution, the descent of all living species from a common ancestor. This important period in the history of life extended over millions of years, plenty of time for the evolution of these new body plans (phyla) to occur. Furthermore, the fossil record provides numerous examples of organisms that appear transitional between living phyla and their common ancestors. The ongoing research about the Cambrian period is an exciting opportunity to advance our understanding of how evolutionary processes work, and the environmental factors shaping them.

The major animal body plans that appeared in the Cambrian Explosion did not include the appearance of modern animal groups such as: starfish, crabs, insects, fish, lizards, birds and mammals. These animal groups all appeared at various times much later in the fossil record.³ The forms that appeared in the Cambrian Explosion were more primitive than these later groups, and many of them were soft-bodied organisms. However, they did include the basic features that define the major branches of the tree of life to which later life forms belong. For example, vertebrates are part of the Chordata group. The chordates are characterized by a nerve cord, gill pouches and a support rod called the notochord. In the Cambrian fauna, we first see fossils of soft-bodied creatures with these characteristics. However, the living groups of vertebrates appeared much later. It is also important to realize that many of the Cambrian organisms, although likely near the base of major branches of the tree of life, did not possess all of the defining characteristics of modern animal body plans. These defining characteristics appeared progressively over a much longer period of time.⁴

Interpretations of the “Cambrian Explosion”

Not all scientists accept the idea that the Cambrian Explosion represents an unusually rapid evolutionary transition. The fossil record is notoriously incomplete, particularly for small and soft-bodied forms. Some researchers argue that the apparent rapid diversification of body plans is an artifact of an increase in the rate of fossilization, due in part to the evolution of skeletons, which fossilize more effectively.⁵ Many of the early Cambrian animals possessed some type of hard mineralized structures (spines, spicules, plates, etc.). In many cases these, often very tiny, mineralized structures are all that are found as fossils. There were major changes in marine environments and chemistry from the late Precambrian into the Cambrian, and these also may have impacted the rise of mineralized skeletons among previously soft-bodied organisms. ⁶

Most scientists are persuaded that something significant happened at the dawn of the Cambrian era and view the Cambrian Explosion as an area of exciting and productive research. For example, scientists are now gaining a better understanding of what existed before the Cambrian Explosion as a result of new fossil discoveries. Recent discoveries are filling in the fossil record for the Precambrian fauna with soft-bodied organisms like those in the Ediacaran Assemblages found around the world.⁷ Late Precambrian fossil discoveries also now include representatives of sponges, cnidarians (the group that includes modern jellyfish, corals and anemones), mollusks and various wormlike groups. Some of the new fossil discoveries, in fact, appear to be more primitive precursors of the later Cambrian body plans. The discovery of such precursors shows that the Cambrian organisms did not appear from thin air.⁸ Further discoveries will no doubt reveal more clearly the relationship of Precambrian organisms with the creatures found in the Burgess Shale and Chengjiang deposits.⁹

Genomic studies provide further insights into the origins of the Cambrian Explosion. Although the genetic divergence of organisms would have preceded the recognition of new body plans in the fossil record, accumulating genomic data is broadly consistent with the fossil record.¹⁰ Both point to the rise of the bilateria (bilaterally symmetric invertebrate animals) in the latest Precambrian Ediacaran, and their ecological explosion in diversity in the Cambrian.

Unanswered Questions

The sudden change of the Cambrian Era was, in relative terms, not too sudden for the process of evolution. The changes during the Cambrian Era did not occur over decades, centuries, or even thousands of years; they occurred over millions of years—plenty of time for evolutionary change. However, for millions of years beforehand, body plans of animals had remained relatively constant. Not until this time period did a significant change occur. The remaining questions are: What triggered the Cambrian Explosion? And why did so much change occur at this time? Several different theories address the origin of the Cambrian Explosion, proposing that dramatic environmental changes must have opened up new niches for natural selection to operate upon. These proposals include the runaway glaciation theory,¹¹ which proposes that glaciers briefly covered much of the earth, and the resultant loss of habitat created bottlenecks where evolution could act more rapidly. Another theory suggests that a change in atmospheric oxygen led to this sudden burst in evolutionary changes.¹² Yet another proposal is that major changes in the seafloor, from algae mat-covered surfaces in the late Precambrian to soft muddy bottoms later in the Cambrian, had dramatic evolutionary and ecological impacts.¹³

The Cambrian Era Fossils, Providing Answers

While the causes of the Cambrian Explosion remain a topic of open and exciting debate, the continued fossil discoveries from the Cambrian and Precambrian Eras are bringing more clarity to the evolutionary puzzle. These fossils provide valuable insight, particularly for envisioning the common ancestors of diverse groups. For instance, both vertebrates (fish) and echinoderms (sea urchins, starfish) are part of the group called deuterostomes. Without fossil evidence, it is hard to envision what a common ancestor would look like for these very different creatures. The Cambrian fossils are filling in the picture.¹⁴

When scientists investigate God’s creation, they find that humans appear very late in the history of life. The fossil record shows that many creatures died long before humans appeared. In fact, many entire species went extinct millions of years ago (the dinosaurs are the most famous example), long before humans lived or sinned.

See “What does the Fossil Record Show?” and “How are the ages of the Earth and universe calculated?”

Yet God’s revelation in scripture paints a different picture. Several key scripture passages teach that death is a consequence of sin, including Genesis 2:16-17, Genesis 3:19,22, Romans 5:12-21, and 1 Corinthians 15. How should we think about these passages in light of the scientific evidence? Could animals have died before human sin? Does “death” in these passages refer to physical death, or spiritual death, or sometimes one and sometimes the other? To ponder these questions, we need to consider God’s revelation in scripture and God’s revelation in nature. The scientific evidence is discussed in other Questions, as are the topics of the fall and sin (see sidebars). Here we consider what scripture says about death and how the two revelations might be reconciled.

See “How does original sin fit with evolutionary history?”

Animal Death

The Bible passages that teach about sin and death are clearly referring to the death of humans. Do these passages also refer to animals? Thomas Aquinas (1225-1274) didn’t think so. He believed that God’s original creation included animals that killed each other, writing that “the nature of animals was not changed by man’s sin.”¹ Pastor Daniel Harrell makes a logical argument for animal death, writing that “there had to be death in the Garden, otherwise Adam would have been overrun by bugs and bacteria long before he took that forbidden bite of fruit.”² Animal death is also necessary to maintain population levels in a balanced ecosystem (see below for more). Some Bible passages portray predatory animals as part of God’s original plan for creation (Job 38:39-41, 39:29-30, Psalm 104:21,29). Other passages speak of the “wolf laying down with the lamb” instead of killing the lamb (Isaiah 11:6-7, Isaiah 65:25), but these verses refer to the future kingdom of God, not the original creation. While animal death and suffering raises other theological questions (see Sidebar), it does not contradict Biblical teaching about death as a consequence of sin.

See “How does the evil and suffering in the world align with the idea of a loving God?”

Human death: physical or spiritual?

One traditional interpretation of Genesis 2-3 is that sin results in physical death. Humans would have been immortal without sin. In Genesis 2:17, God warns Adam and Eve, “But of the tree of the knowledge of good and evil you shall not eat, for in the day that you eat you shall die.” In Genesis 3:19, God carries out this punishment, cursing Adam with labor and death, “By the sweat of your brow you will eat your food until you return to the ground, since from it you were taken; for dust you are and to dust you will return.” In 1 Corinthians 15 Paul contrasts and compares Christ and Adam, highlighting Adam’s fall as the cause of physical death for the whole human race.

John Calvin, however, suggested that Adam’s sin caused the abrupt painful death that we experience today, a wrenching apart of the physical and spiritual aspects of humans. Calvin seems to have thought that if Adam had not sinned, a more gentle kind of physical death or “passing” from life into life would have occurred: “Truly the first man would have passed to a better life, had he remained upright; but there would have been no separation of the soul from the body, no corruption, no kind of destruction, and, in short, no violent change.”³ In this view, humans were created mortal, but intended for long healthy lives and graceful deaths, such as described in Isaiah 65:20-25. The Old Testament speaks of death at the end of a long life in purely positive terms, such as 1 Chronicles 29:28 where King David “died at a good old age, having enjoyed long life, wealth, and honor.”

Another interpretation of these passages is that the consequence of sin is spiritual death, not physical death. If Adam had not sinned, humans would still have died like we do today, but without “the sense of loss, uncertainty about an afterlife, … and regret for unfinished work” that comes with spiritual death.⁴ Agemir de Carvalho Dias, Presbyterian pastor and teacher of the Evangelical College of Parana, Brazil, writes that “the death that entered the world with Adam is understood as something that takes man apart from God, a spiritual death, in the sense that the access to God is now closed and can be restored only through faith.”⁵ Of course some sins still bring about physical death, such as Abel’s death at Cain’s hand, and the death of King David’s infant son after the king’s adultery (2 Samuel 12:13-14).

The text of Genesis 2-3 can support an interpretation of the curse as spiritual death. In the curse of Genesis 3:19, God tells Adam “for dust you are and to dust you will return,” implying that Adam was created mortal from the dust. God warned Adam and Eve that they would die in the day they ate from the tree, and yet Adam lived to the age of 930 (Genesis 5:5). What did happen on the day they ate from the tree? Adam and Eve felt shame and were expelled from the Garden, breaking their fellowship with God – spiritual death.

Weren’t Adam and Eve immortal, created as perfect ideal human beings? This is a popular idea, but not clear in the Biblical text. The first humans are described as “very good” and pleasing to God (Genesis 1:30-31), but not as perfect or with superhuman abilities. Also, consider the Tree of Life. God planted this tree in the garden before the fall (Genesis 2:9) and it gives immortality to the one who eats it (Genesis 3:22). If God created humans as immortal, what was the purpose of the Tree of Life? It would only be needed if humans were mortal to begin with.⁶

In the New Testament, Paul writes much on the relationship between sin and death. Sometimes Paul was clearly referring to spiritual death (Romans 6:1-14, 7:11), and other times clearly to physical death (1 Corinthians 15:35-42). Yet even in 1 Corinthians 15, Paul writes of the eternal life in Christ as something much more than the mere earthly life we experience now, implying that “death” also refers to much more than mere physical death. This is more explicit in Romans 5:12-21 where death is contrasted with the gifts of grace, justification, and righteousness, i.e. the new spiritual life provided by Jesus’ victory.

See “Were Adam and Eve Historical Figures?” which discusses the issue of death and the identity of Adam and Eve

Could physical death be part of God’s original plan?

The Garden of Eden has a reputation as a perfect place, with no death, pain, or even danger for humans or animals. Yet Genesis only teaches that the original creation is “good”, not “perfect.” Some verses in Genesis 1-2 suggest that God’s creation was not safe or pain-free. D. C. Spanner points out that God charged humanity to “subdue” (Genesis 1:28), a word that implies danger.⁷ Also, Genesis 2 places Adam and Eve in a garden; in the ancient near east, this was a walled enclosure, protecting the inhabitants from the wilderness and dangerous animals beyond. The Bible is clear that the culmination of God’s plan in the new creation is a place without tears, pain, or death (Revelation 21:4), but is less clear whether the first creation shared these traits.

The death of plants and animals is actually an essential feature in a healthy ecosystem. Plants provide food for animals, and animals return nutrients to the soil upon their deaths. Without predators, populations of some species would explode and crowd out others, maybe even pushing those species to extinction. Predators tend to pick the most populous species to eat, limiting its growth so that other species can compete successfully.⁸

It is more difficult to see human death in a positive light. For those who have lost a loved one, death can feel like the ultimate evil.⁹ Jesus mourned the death of his friend Lazarus (John 11), after all. Paul writes of death as the paycheck for sin (Romans 6:23) and as the last enemy to be destroyed (1 Corinthians 15:26). The New Testament seems to emphasize death as an evil because it is incompatible with the kind of life promised in the fulfilled kingdom of God. Jesus’ earthly ministry signified the arrival of that future kingdom of God into the present age, but we still live in a world in which the kingdom has not been fully realized. Thus the continuing reality of physical death clashes with the promise of the redeemed future. Only when believers are clothed with their new resurrection bodies will death be finally conquered.

Yet death also appears in the Bible as the utmost expression of love—part of God’s plan for ushering in that new kingdom. Jesus said that the greatest love one can show is to lay down one’s life for another (John 15:13). He then proceeded to lay down his own life for us while we were still sinners (Romans 5:6-8). Christianity holds up the cross as the supreme demonstration of sacrificial love. Jesus said, “Unless a kernel of wheat falls to the ground and dies, it remains only a single seed. But if it dies, it produces many seeds” (John 12:23-25). Jesus thus pointed to the role of death in a healthy ecosystem as a parable for the importance of His own death. Just as the death of an organism allows for the rebirth and flourishing of life, so the death of Jesus leads to a rebirth and new life for Jesus’ followers. Perhaps the biological death in the evolutionary epic was not a purposeless waste, but a hint at the way God redeems the negativity of death for the sake of new life.

Behe suggests that the parts of irreducibly complex biological structures would be useless unless they appear all together, and evolution has no mechanism to build complex structures like this. Natural selection, after all, works just one step at a time. Furthermore, natural selection has no foresight. Put simply, if a change is going to be preserved, that change will generally need to confer some extra benefit—no matter how small—to the next generation. Behe has oversimplified things a little. Evolutionary theory predicts that in small populations, neutral changes—and even changes that are slightly deleterious—will survive sometimes. Still, in general, he is correct. So let’s examine what evolutionary biologists believe about how complex structures are built.

A Seemingly “Irreducibly Complex” System

As Scott Gilbert shows in his textbook Developmental Biology, Eighth Edition, the evolution of the interconnecting bones of the middle ear illustrates how supposedly irreducibly complex structures can in fact be generated by the stepwise process of gradual change and natural selection. Fish, for example, have a special system called the lateral line system that extends along the length of their bodies and enables them to detect vibrations in the water. They also have an inner ear, which is useful for balance and supplements the lateral line system in detecting vibrations. With the movement of certain water-dwelling species to land, the lateral line system became obsolete because what was needed was a way of amplifying the vibrations in air, not water. A bone that had previously been used as a support for the skull became the stapes. Along with supporting the skull, the stapes also transmitted sound vibrations—which come in part through the skull and jaw—to the inner ear. How do we know it’s the same bone? By examining its embryological origin in fish and reptiles. In reptiles, there is just one bone that transmits air vibrations to the inner ear: the stapes.

We can also trace the origin of the two other middle ear bones, the incus and malleus, by looking at fossils from the time of the origin of mammals about 230 million years ago. Until that point, two bones—the articular and quadrate bones—served as the hinge of the jaw. Investigators, however, believe they carried out a second function. Because they were located adjacent to the stapes, it is likely they also aided in transmitting sound vibrations to the stapes.

Here is where the story gets especially interesting. Right at the time of the origin of mammals it turns out there were several species—perhaps many, paleontologists are sure they don’t have all of the transitional species preserved in the fossil record—that had a double hinge at the jaw. Not only did the articular/quadrate bones serve as a hinge, but another pair of bones, the dental/squamosal bones, served that purpose as well. So the articular/quadrate bones, which transmitted sound, no longer had to also serve as a jaw-hinge. This second function became redundant because there was another set of bones doing the same thing.

With that redundancy, the articular/quadrate bones of the jaw were free to become the incus/malleus of the middle ear. We have a record of the transition, and we have a record of the building of a so-called irreducibly complex structure. Parts that were initially used for one function became, for a period of time, useful for two functions. Then, one function was refined while the other function became redundant or unnecessary. In other words, parts that were initially used for one purpose become co-opted for another purpose; and looking back through the fossil record, we can see the intermediates.

The Bacterial Flagellum

In Darwin’s Black Box, Behe focuses on three things he considers to be irreducibly complex: the bacterial flagellum, the blood clotting cascade and the immune system. The elements of these systems are molecular in nature and therefore the evolutionary intermediates are somewhat harder to document. Interacting molecules are not preserved for historical analysis like fossil bones of the skull and middle ear. In his book, Behe suggests that biochemistry gives no clue as to how complex interacting parts like these might have come about, and he confidently states that investigations have run up against a blank wall.

It has now been 13 years since Darwin’s Black Box was written. The structures and processes Behe chose to focus on have been studied quite extensively. Although it is impossible to go back and analyze step by step what actually did happen, much evidence for straightforward evolutionary explanations has accumulated over the years. The diversity in a given structure that we see when we compare different species tells us a great deal about how that structure might have come about.

Consider the bacterial flagellum, the example most commonly used to illustrate the principle of irreducible complexity. First, it is important to point out that the bacterial flagellum comes in many different varieties, sometimes with profound differences between one species and another. This alone illustrates that the flagellum is probably not irreducibly complex. It can be altered, and when it is altered, it does not necessarily lose its function.

There are many species of bacteria, for example, that use the basal parts of the flagellum to deliver toxins into their host. A different set of bacterial species uses a portion of the flagellar machinery for another purpose. Species of the genus Buchnera live inside the sheltered environment of aphid cells in a symbiotic relationship. These bacteria no longer need flagella. However, each tiny Buchnera cell is studded with hundreds of copies of the flagellar base. As a recent paper in the journal Trends in Microbiology shows, the purpose now is to serve as a passageway for the export of proteins and other material into the surrounding environment—the aphid cell in which the bacterium resides. So while we cannot follow the sequence of events step by step to illustrate how the various types of flagella have arisen, we can see how they have changed and, in some cases, even taken on whole new functions. The term for adapting a structure for a different purpose than that for which it originally arose is “exaptation.” This is one important way in which complexity arises.

That is not the whole story, however, because individual parts have to be added into the structure as it becomes more complex or takes on new function. Where do those parts come from? Recently, investigators have shown that the key protein in the molecular motor that causes the flagellum to rotate has a very similar structure to another protein that is used to transport magnesium into and out of cells. Both protein molecules have sections that fold in almost exactly the same manner, and when we analyze the order of their building blocks (amino acids), we see profound similarities. This illustrates a second principle in building complexity: It is done by co-option. Parts that are used for one purpose are co-opted to take on a second function as well. Sometimes, the instructions to build a part are encoded by identical duplicate genes. When that happens, co-option is especially straightforward. One set of instructions for making the original part is preserved while the duplicate set of instructions can gradually be modified through mutation and natural selection, allowing the part to become better and better at carrying out its new function. This illustrates a third principle of assembling complexity: adaptation through natural selection.

Even more revealingly, the supposedly irreducibly complex bacterial flagellum turns out not to be irreducible after all. For example, there is a protein at the base of the flagellum, an ATPase, that drives the key structural subunit (flagellin) of the long hollow tube through its inner core, causing the flagellum to grow in length. Yet, it has been shown that flagellin can be transported to the end of a flagellum without this ATPase. The protein that was thought to be one of the flagellum’s most important parts can be done away with. This illustrates a fourth principle of building a complex structure: redundancy. Inside of cells, there is often more than one way to accomplish a particular purpose; as evolution “tinkers” with a complex structure, there is likely to be redundancy with certain parts at certain stages. One of these redundant mechanisms may become more specialized, and even perfected, as time goes by.

The Eye

Another system that is often held up as an example of irreducible complexity is the eye. People often ask: What good is a partly assembled eye? Is there any logical series of steps that could result in the creation—through the process of natural selection—of a structure so elegant as the eye of an eagle? What would be the starting point, anyway?

Watch "The Evolution of the Eye" from PBS' Evolution: "Darwin's Dangerous Idea".

All light-sensing devices in the animal world make use of a single light-sensitive molecule, retinal, which is derived from Vitamin A. Retinal can change its shape when it absorbs a photon of light. This molecule is always complexed with a protein known as an opsin. The two work together to sense light.

By analyzing the arrangement of the building blocks, or amino acids, in opsin, it is possible to show that all opsins are derived from a single ancestral gene. What purpose could the retinal/opsin combination have had in the earliest days of animal history? It likely functioned to detect light in order to set the internal body clock that regulates the 24-hour cycle of biological processes, known as the Circadian rhythm. In recent years, it has become apparent that living processes inside of cells are tuned to function in a manner that is synchronized with the cycle of sunlight.

Circadian rhythms function throughout the living world, including single-cell organisms. It seems likely, then, that the simplest light-detecting device arose through exaptation of a molecular device that was used to detect light—not so that an organism might move toward or away from the light, but so it could reset its molecular clock. Even the origin of opsin illustrates a basic principle of building complexity, co-option. Opsin is one of many G-protein receptors, which have come to take on many different functions through the history of life. When coupled with the light-sensitive molecule retinal, a G-protein receptor allows the cell to be sensitized to the presence and absence of light. Although we have no fossilized transitions that allow us to trace the various eye intermediates that have occurred in animal history, as we do with the middle ear, we do have a myriad of light-sensing devices in the animal kingdom that allow us to piece together how sophisticated eyes could have been created through a gradual process driven by natural selection. (You can read more about the prospective intermediates that exist in the animal world in a wonderful paper by Ryan Gregory.)

If you choose to explore eye development in detail, be watching for examples of exaptation, co-option, step-by-step adaptation and redundancy. For example, you will note that the evolution of the lens illustrates co-option and redundancy. There are two ways to focus the image on the light-receiving cells at the back of an eye. One way is through an independent lens. The other way is through the transparent cornea in front of the lens. The lens is simply transparent crystallized protein molecules that are assembled in such a manner that they bring the image into sharp focus. There are a variety of proteins that can be crystallized to serve as an effective lens. It turns out that, depending on the evolutionary lineage, various proteins—including enzymes such as alcohol dehydrogenase (an enzyme for breaking down ethanol), glutathione S transferase and protein chaperones—are used for this purpose. This is a simple example of co-option and redundancy functioning together as part of the tinkering mechanism used for building a complex structure like the eye.

Two-thirds of animal phyla have some sort of light-sensing device. Although all of these light-sensing devices make use of retinal and opsins, there are differences in structure that we can trace to differences in evolutionary origin. In his 2003 book, Life’s Solution, Simon Conway-Morris documents at least seven independent origins of the eye resulting in very similar outcomes. For example, the eye of a squid and the eye of a mammal work in a remarkably similar manner. However, the ways the two eyes are constructed during development are quite different. Differences in structure are constrained by how particular bodies are constructed as the embryo develops. Eyes also bear telltale signs of the fact that there has been a certain amount of jury-rigging in their construction. They are not perfect. They have blind spots, are subject to retinal detachment, glaucoma and macular degeneration, all of which are a function of the history of how the eye has been assembled through time.

Read how a recent study has shot down the idea that protein transport is irreducibly complex.

Although we don’t have the eye intermediates preserved in stone the way we can see the simpler assembly of the parts of the mammalian middle ear, we do have a vast array of eye structures in the animal kingdom, any one of which might appear to be irreducibly complex but which, in fact, has been put together through a set of processes that has included exaptation, co-option, step-by-step adaptation and some redundancy at various stages along the way. Indeed, these eye structures themselves are likely intermediates. Everything changes as it passes through the eons of time. This is the legacy of creation through the process of natural selection.

The “image of God” is a key concept in Christian theology, foundational to Christian thinking about human identity, human significance, bioethics, and other topics. Many Christians see evolution as incompatible with the image of God. How could God’s image bearers have evolved from simpler life forms? Doesn’t image-bearing require miraculous creation of humans rather than shared ancestry with chimpanzees? And when in the evolutionary process did humans attain this image? These questions are tied to many other issues concerning human origins, including the soul, the Fall, and the historicity of Adam and Eve (see sidebars), but in this article we will focus specifically on the image of God.

See “How does the Fall fit with evolutionary history?” and “Were Adam and Eve historical figures?”

The phrase “image of God” does not appear many times in the Bible, but the importance of the concept is emphasized by its repetition in the creation account:

Then God said, “Let us make mankind in our image, in our likeness, so that they may rule over the fish in the sea and the birds in the sky, over the livestock and all the wild animals, and over all the creatures that move along the ground.” So God created mankind in his own image, in the image of God he created them; male and female he created them. -- Genesis 1:26-27

From this text, it is clear that part of bearing God’s image is ruling over the animals. Genesis 9:5-6 reveals another aspect of image bearing: all human lifeblood is sacred because all humans are made in the image of God. The emphasis on Judeo-Christian thought on the sanctity of human life is derived in part from this passage. In the New Testament, the idea is expanded further as Christ is revealed as the true image of the invisible God (2 Corinthians 4:4, Colossians 1:15).

For centuries, theologians have discussed these and other passages, debating the meaning of the image of God (“imago Dei” in Latin). Being made in God’s likeness is not a matter of our physical appearance, because humans don’t all look the same. But to what does the image of God actually refer? Many ideas have been suggested over the centuries, producing a huge body of theological writing. While hard to summarize, we give a brief overview below of three common themes for the image of God. After developing this theological context, we’ll consider how these ideas intersect with evolution.

Image of God as our abilities

A common view is that the image of God refers to human abilities. When people talk of the things “that make us human,” they refer to abilities like reason and rationality, mathematics and language, laughter and emotions, caring and empathy, and cultural products like music and art. Often the motive is to distinguish humans from animals by showing that humans have unique abilities that make us special and superior to animals. Saint Augustine (354-430 A.D.) wrote something like this when he said “Man's excellence consists in the fact that God made him to His own image by giving him an intellectual soul, which raises him above the beasts of the field.”¹ Saint Thomas Aquinas (1225-1274 AD) also emphasized intellect and rationality in his discussion of image bearing.² But Augustine and Aquinas were not speaking of intellect as an aptitude for math or music; Aquinas instead writes of an “aptitude for understanding and loving God.” In fact, the modern emphasis on reason comes more from secular Enlightenment ideas than from Christian theology. During the Enlightenment, the image of God was connected to ideas like the natural dignity and majesty of humankind that separates us from the brute beasts of the animal world.

Scientific evidence is piling up that humans have more in common with animals than was once thought. Genetic evidence shows that humans and chimpanzees share much of their DNA. Studies of animal behavior (particularly of chimps and other apes) show that animals not only laugh and cry and care for each other, but can learn sign language and even have basic reasoning ability. In fact, Christian neuroscientist Malcolm Jeeves writes that “any attempt to set down a clear demarcation between the reasoning abilities of nonhuman primates and humans is found to have become blurred.”³ Obviously, humans have a much larger capacity to reason than animals, but reasoning is not a uniquely human ability. As neuroscientists and animal behaviorists learn more about animals, they see how traits appear in a rudimentary form at a level similar to human children.⁴ Whether or not one accepts evolution, evidence from living humans and animals does not show a distinct difference in kinds of abilities (only degree).

See “Made in the Image of God: The Theological Implications of Genomics” a 2-part blog by Denis Alexander.

Another challenge for this picture of the image of God is the place of people with mental disabilities. If a person is impaired in reasoning or language, are they bearing less of God’s image? Are they not showing his true likeness? The Christian answer to these questions is No! The Bible repeatedly teaches that God values all people, particularly those who are rejected by society or unable to care for themselves.⁵ In fact, Genesis 9:5-6 points to image bearing as the reason that all human life is valuable. This is a major motivator for Christians who seek to protect the unborn, the poor, and the aged. Surely bearing God’s image must mean something other than using our abilities.

Image of God as our spiritual capacities and relationship with God

Another common view is that the image of God refers to our capacity for a relationship with God. Following Aquinas’ view of “aptitude for understanding and loving God,” the Catholic catechism says,

Of all visible creatures only man is able to know and love his creator. … he alone is called to share, by knowledge and love, in God's own life. It was for this end that he was created, and this is the fundamental reason for his dignity. Being in the image of God, the human individual possesses the dignity of a person, who is not just something, but someone. He is capable of self-knowledge, of self-possession and of freely giving himself and entering into communion with other persons. And he is called by grace to a covenant with his Creator, to offer him a response of faith and love that no other creature can give in his stead.⁶

John Calvin (1509-1564) and other reformers ⁷ wrote of the image of God as the original righteousness of humans before the Fall. When first created, we reflected God’s “wisdom, righteousness, and goodness”⁸ but, as Paul teaches, that image was tarnished by sin and is being restored in Christ:

Since the image of God had been destroyed in us by the fall, we may judge from its restoration what it originally had been. Paul says that we are transformed into the image of God by the gospel. And, according to him, spiritual regeneration is nothing else than the restoration of the same image. (Colossians 3:10, and Ephesians 4:23.) -- John Calvin, Commentary on Genesis ⁹

Neuroscientists have also attempted to investigate this model, looking for evidence of such things as selfless behavior or the ability to perceive the transcendent. But science is simply not capable of fully testing such spiritual realities; the evidence that scientists do find is open to many interpretations.¹⁰

Image of God as our commission

What did the “image of God” mean to the first audience of Genesis 1? We get insights from the rest of the Old Testament, which frequently uses “image” in the context of idol worship. In the ancient cultures of Egypt and Canaan, people made images of their gods from metal and wood and set them up in local temples to worship. Hebrew scholar Joseph Lam writes that the idol “was believed to be the true manifestation of the god in the midst of the people.”¹¹ In the Ten Commandments, God prohibits his people from making such images (Exodus 20:4-6), because God cannot be contained in, or even represented by, an idol made by human hands (see Isaiah 44:6-20). Israel’s temple contained no representation of God himself.

Turning back to Genesis 1, we now see “image of God” in a new light. The image is not a built-in ability or capacity of human beings, but a role we are called to live. God has named us as his living images. We represent God here on earth, better than any idol made by human hands. Lam writes:

In fact, it is possible to argue grammatically for the validity of the translation ‘as the image of God’ as opposed to ‘in the image of God’. … The Hebrew phraseology here denotes not so much the manner of the creation of the human being (i.e. the “mold” out of which humans are created), but rather the intended function of the human being in the world. Humans aren’t just made in God’s image, they are called to be his image in the world.¹²

Joshua Moritz develops this idea further, pointing out the parallels of our appointment to the role of image-bearer with other instances of divine election.¹³

Watch a short video where N. T. Wright describes image bearing as an angled mirror, reflecting God’s love to others and reflecting the praise of the world back to God.

Connections to evolution

How might these models of the image of God fit with evolution? First recall these key points from the BioLogos faith statement¹⁴:

• We believe that the diversity and interrelation of all life on earth are best explained by the God-ordained process of evolution and common descent. Thus, evolution is not in opposition to God, but a means by which God providentially achieves his purposes.

We believe that God created humans in biological continuity with all life on earth, but also as spiritual beings. God established a unique relationship with humanity by endowing us with his image and calling us to an elevated position within the created order. Thus, BioLogos believes that God created humanity using the process of evolution and endowed us with his image. Both views of the image of God (“spiritual capacity” and “commission”) are compatible with the scientific evidence for evolution, and both views are affirmed by individuals in the BioLogos community. In fact, the two views are not mutually exclusive.

If the image of God refers to our spiritual capacities, God could still have used the natural process of evolution to create our bodies and human abilities. God could have used a miraculous process to create our spiritual capacities, or used some combination of natural processes and divine revelation to develop these capacities. Either way, God is the creator of our whole selves, including both our physical and spiritual aspects.

If the image of God refers to our commission, then it has little impact on one’s view of how God created humans. Whether God made the first humans using natural processes or a single miracle or a mixture of the two, God named humanity as his image bearers.

BioLogos welcomes more evangelical scholarship on this question.

Living out our calling as image bearers

While the academic debate is important, it should not distract us from the essential calling to live as people created in God’s image. Let us remember to

• Value every person as a fellow image bearer. All people, both men and women, are created in the image of God (Genesis 1:26-27), not just some priestly class. All of humanity is equally valued in God’s eyes, and should be in ours (Genesis 9:5-6).
• Seek to attain the whole image of God in Christ (Ephesians 4:23). As the Holy Spirit works in us to bring about the new self, we are being molded more and more into the true image of the Creator.
• Care for the creation. As representatives of the Creator, we are charged to rule over the Earth and subdue it (Genesis 1:26-28) which includes helping creatures fulfill their God-given mandate to be fruitful and multiply (Genesis 1:22) and tending the garden God provided (Genesis 2:15).¹⁵
• Worship the Creator. Of all the created order, humanity is the leading voice to speak our praise back to the One who made us.

It would be difficult to give a short answer to this complex question.  From all we know about the state of the Earth 3 to 4 billion years ago and what we know about the complexity of the building blocks of life — DNA, RNA, amino acids, sugars — no entirely plausible hypothesis for the spontaneous origin of life has been found.  Because the topic does not have as many potentially useful applications as other areas of science, less research has traditionally been performed in this area. However, scientists are currently approaching this challenge from a number of different perspectives.¹ The fact that there is no answer today does not mean there will be no answer tomorrow.  Though an explanation for the origin of life is currently elusive, this does not mean divine intervention is the only possible explanation. There are many unexplained natural phenomena; the origin of life is simply a particularly compelling example of an unsolved mystery we would like to understand.

Clarifications

In discussions about the origin of life, an important first step is clarifying what is meant by life.  The first forms of life on Earth were probably very different from what we would call life today.  It may be tempting to think of life as anything containing the DNA double helix seen in many life forms today.  However, the main property required for early life is self-replication. The earliest self-replicating systems could have been made out of DNA, RNA or some other basic building blocks.  The key feature of such systems would have to be the ability to gather chemicals from the local environment and make copies of themselves.  All life on Earth contains carbon as an essential elemental building block.²  Carbon is the simplest element capable of forming the remarkably complex molecules that are so prevalent in life forms. Therefore, it is likely carbon was involved from the beginning.  Compounds containing carbon are generally categorized as organic; and exploring the natural mechanisms that create complex organic compounds is a main focus in research on the origins of life.

It is also important to keep in mind the age of the Earth. The Earth is approximately 4.5 billion years old.  All evidence suggests that the Earth was inhospitable to life for the first 700 million years, largely because it was so hot. However, the Earth gradually cooled, and 4 billion years ago it became more hospitable. Within little more than 100 million years, the first single-cell life forms appeared.³  Where did these organisms come from? And what were their capabilities?  Although we do not know the path that led to these early bacterial forms, it seems likely DNA had emerged as the information molecule by this time.  Microbiologist and physicist Carl R. Woese suggests there was a considerable amount of lateral gene transfer among the first forms of bacteria called archaebacteria.⁴ Lateral gene transfer, which is the movement of genes from one bacterium to another, would have enabled the exchange of genetic material, and it would therefore expedite the process of diversification of biological function acted upon by natural selection.  How these first organisms ever developed in the first place is the topic of the following discussion.

The Miller-Urey Experiment

Charles Darwin is often credited for the original “warm little pond” hypothesis, which proposes life may have formed from a combination of inorganic compounds and energy.⁵ Soviet biochemist Aleksandr Ivanovich Oparin revisited this idea and proposed life formed in an environment that lacked oxygen but was energized by sunlight.⁶  These kinds of ideas are the basis of much research of life’s origins, including the famous Miller-Urey experiment.

In 1953 at the University of Chicago, Stanley Miller and Harold Urey tackled the problem of the origin of life by reproducing the conditions they believed to be present on the primitive Earth when life originated.  By zapping a mixture of water and inorganic compounds with electricity, they produced organic compounds including amino acids, the building blocks of protein.⁷ This result catalyzed further experiments — and at least to some, it appeared that the solution to life’s mystery was about to unfold. 

A subsequent discovery by Joan Oro at the University of Houston, published in 1961, demonstrated that an essential component of DNA — adenine — as well as several amino acids could be formed by heating the inorganic compound hydrogen cyanide in water-ammonia.⁸  Though this work potentially contributed useful pieces to the puzzle,⁹ Miller-Urey type experiments have fallen short of providing a full answer to how life originated.  It’s one thing to have organic compounds present, it’s quite another to have them form a self-replicating system.

Recently, these initial results were revisited with more sensitive methods. Researchers discovered additional amino acids and other building blocks formed during the Miller-Urey experiments that they originally had not realized.¹⁰ Miller continued a variety of experiments to pin down life’s origins and, though the mystery remained unsolved, members of his lab discovered amino acids and other building blocks for life can also form from inorganic compounds in extremely cold environments.¹¹

How Life Came Together

Explanations of how the amino acids, nucleotides and sugars were formed, how they assembled in the form of DNA and RNA, and then how these building blocks of life came to replicate themselves and acquire the enzymes to facilitate this process, are all still speculative.  Many interesting ideas are being researched, however, including the deep sea vent theory,¹² radioactive beach theory¹³ and crystal or clay theory.¹⁴ Another opinion, held by Francis Crick and others, is that the only explanation for life on Earth is that it came from another planet.¹⁵  However, this type of explanation only pushes the question farther back: How did this extraterrestrial life originate? A compelling explanation of the origin of life here on Earth has not yet emerged.

Evolutionary theories of how life originated fall in two main camps: the gene first hypothesis and the metabolism first hypothesis. The gene first hypothesis currently focuses on RNA rather than DNA, as certain RNA molecules have shown the ability to function as enzymes, suggesting RNA could have both carried information and copied itself.  From this point of view, RNA preceded both DNA and protein synthesis.  On the other hand, the metabolism first hypothesis argues the molecules of prebiotic materials formed chemical cycles and networks of chemical reactions that gave rise to primitive metabolic systems.  These metabolic systems existed before RNA and provided the environment for RNA replication to later emerge.  Despite the exploration of numerous avenues of research, both theories currently lack conclusive evidence.  While researchers have recently generated self-replicating RNA from prebiotic molecules in the laboratory,¹⁶ it is difficult to understand how RNA — a notoriously unstable polymer — could have supported self-replicating systems in the hostile chemical and thermal environment of early planet Earth.

Conclusion

The study of life's origins is an exciting area of research.  The jury is still out on how life first emerged. A simple response would be to give a God-of-the-gaps explanation: that some supernatural force, namely God, must have intervened to bring life into being.

See "What is evolution?".




 

But consider the timeline of these scientific quandaries.  Life on this Earth appeared approximately 3.85 billion years ago, yet serious scientific study of its origins began just 60 years ago.  A convincing scientific explanation may still emerge in the next 50 years. Though the origin of life could certainly have resulted from God’s direct intervention, it is dangerously presumptuous to conclude the origin of life is beyond discovery in the scientific realm simply because we do not currently have a convincing scientific explanation. Although the origin of life is certainly a genuine scientific mystery, this is not the place for thoughtful people to wager their faith. All that has happened in the history of life has happened in response to God's creation command (John 1:3).  Furthermore, God is immanent in creation, upholding the natural laws.  Colossians 1:17 tells us, "He is before all things, and in him all things hold together."  What we do not know at this point is the extent to which God may have intervened supernaturally in the history of life.  Some believe that the creation command was carried out through the natural laws which have been continuously upheld by the ongoing presence of God in creation.  Others believe that since the God of the Bible and the God we experience in our lives intervenes in supernatural ways at times, that this would also likely have been true in the history of life itself.  Neither of these views are inconsistent with scientific findings.  The important thing is that in the BioLogos view, God’s sustaining creative presence undergirds all of life’s history from the beginning to the present.

Finally, as a purely technical matter, the theory of evolution does not propose an explanation to the question of the origin of life at all. The theory of evolution becomes relevant only after life has already begun.

A common argument against evolution is that the theory contradicts the Second Law of Thermodynamics that claims disorder, or entropy, always increases or stays the same over time.  This law has plenty of everyday examples. Buildings break down over time, and food spoils if not eaten soon enough.  In both cases, the amount of disorder increases with time, but the opposite is never true. Buildings don’t strengthen themselves, and no amount of waiting will cause rotten food become edible again.  But because evolution results in an increase in the order and complexity of species — which is a decrease in entropy — some critics claim evolution violates the Second Law of Thermodynamics.

Defining the System

However, this objection is grounded in a misunderstanding of the second law, which states any isolated system will increase its total entropy over time.  An isolated system is defined as one without any outside energy input. Because the universe is an isolated system, the total disorder of the universe is always increasing.

With biological evolution however, the system being considered is not the universe, but the Earth. And the Earth is not an isolated system.  This means that an increase in order can occur on Earth as long as there is an energy input — most notably the light of the sun. Therefore, energy input from the sun could give rise to the increase in order on Earth including complex molecules and organisms.  At the same time, the sun becomes increasingly disordered as it emits energy to the Earth. Even though order may be increasing on Earth, the total order of the solar system and universe is still decreasing, and the second law is not violated.


Misapplication of The Second Law

To claim that evolution violates the Second Law of Thermodynamics is also grounded in a misunderstanding of where the law applies.  Nobody has ever figured out how to apply the second law to living creatures. There is no meaning to the entropy of a frog. The kinds of systems that can be analyzed with the second law are much simpler.

A living organism is not so much a unified whole as it is a collection of subsystems. In the development of life, for example, a major leap occurred when cells mutated in such a way that they clumped together so that multicellular life was possible.  A simple mutation allowing one cell to stick to other cells enabled a larger and more complex life form.  However, such a transformation does not violate the Second Law of Thermodynamics any more than superglue violates the law when it sticks your fingers to the kitchen counter.

There are many examples of order arising from disorder in nature. Research conducted by Ilya Prigogine¹ and others on systems far from equilibrium has shown that order can spontaneously arise in systems that are driven in the right way. It turns out that living systems are characterized as being far from equilibrium.

The Second Law of Thermodynamics also has interesting implications for cosmology, as it requires that universe began in a highly ordered state.

God-of-the-gaps arguments use gaps in scientific explanation as indicators, or even proof, of God’s action and therefore of God’s existence. Such arguments propose divine acts in place of natural, scientific causes for phenomena that science cannot yet explain. The assumption is that if science cannot explain how something happened, then God must be the explanation. But the danger of using a God-of-the-gaps argument for the action or existence of God is that it lacks the foresight of future scientific discoveries. With the continuing advancement of science, God-of-the-gaps explanations often get replaced by natural mechanisms. Therefore, when such arguments are used as apologetic tools, scientific research can unnecessarily be placed at odds with belief in God.¹ The recent Intelligent Design (ID) movement highlights this problem. Certain ID arguments, like the irreducible complexity of the human eye or the bacterial flagellum, are rapidly being undercut by new scientific discoveries.

Illustrating God-of-the-Gaps

The familiar story of Isaac Newton and Pierre Simon de Laplace is a classic example of the God-of-the-gaps argument. Newton devised a mathematical equation for the force of gravity that he used to explain and predict the motions of planets with outstanding accuracy. With pencil and paper, the orbit of the planets around the sun could be calculated with great precision. But planets also have gravitational interactions with each other, not just with the sun. For example, when the Earth passes Mars in its orbit around the sun, there is a small but significant gravitational interaction between Mars and Earth. Because these tiny interplanetary interactions occur often — several times per year in many cases — Newton suspected that these gravitational perturbations would accumulate and slowly disrupt the magnificent order of the solar system. To counteract these and other disruptive forces, Newton suggested that God must necessarily intervene occasionally to tune up the solar system and restore the order. Thus, God's periodic special actions were needed to account for the ongoing stability of the solar system.

See "How is BioLogos different from Theistic Evolution, Intelligent Design and Creationism?" and "How can evolution account for the complexity of life on earth today?"

Newton also thought that God was necessary to explain how the planets all happen to be travelling around the sun in the same direction and in the same plane. His theory of gravity was entirely compatible with planetary motions in any direction and with orbits tilted at any angle to the sun. But this is not what we find. The planets travel in the same direction, and almost all of their orbits are in the same plane. The planets move around the sun like runners on a track: very orderly. Newton thought only God could have set things up so elegantly:

"The six primary Planets are revolv'd about the Sun, in circles concentric with the Sun, and with motions directed towards the same parts, and almost in the same plane. […] But it is not to be conceived that mere mechanical causes could give birth to so many regular motions. […] This most beautiful System of the Sun, Planets, and Comets, could only proceed from the counsel and dominion of an intelligent and powerful Being." ²

In both of these examples — one related to the ongoing motion of the planets and the other related to the origin of the motions — Newton is employing textbook God-of-the-gaps reasoning. Scientific theories are proposed to explain as much as possible, and then God is brought in to cover any remaining unexplained gaps in the explanation.

We now know that Newton was wrong on both counts. The gravitational perturbations that planets experience are so completely balanced that they average out to zero over time. The net result is that the planetary motions are stable; they do not deteriorate over time. And it was a straightforward application of Newton’s theory that revealed this. Newton simply had not done all the calculations to see if his intuition was right. The same was true for the orderly motion of the planets. Newton had no concept of how solar systems could form on their own or what the planetary motions would be like in naturally forming systems. Astronomy simply had not developed to this point. In the decades after Newton, astronomers discovered that solar systems form naturally from large clouds of rotating matter. Therefore, a large, slowly rotating cloud collapses under its own gravity, and it tends to flatten into something like a pancake. Saturn's rings are an interesting example where the cloud is still present. The material collects into big clumps in the plane of the pancake. After the process is completed, a collection of clumps all travelling in the same direction and in the same plane exists — just like our solar system.

Such episodes in the history of science are not unusual. In fact they are so common that the phrase God-of-the-gaps has been coined to label the process of invoking God to account for natural phenomena that is not explained by science. The dangers of such God-of-the-gaps reasoning were highlighted a century after Newton by a situation involving the French mathematician Pierre Simon de Laplace who held a bureaucratic post in Napoleon Bonaparte’s administration. Laplace was the beneficiary of a remarkable century of progress in refining and extending Newton’s laws of motion and expanding the vision of what was going on in space. As a result, he was able to write a wide-ranging text explaining the mechanics of the heavens without invoking divine intervention.

As legend goes, Laplace was questioned by Napoleon about the absence of God in his theory: "M. Laplace, they tell me you have written this large book on the system of the universe, and have never even mentioned its Creator." To this, Laplace famously replied, “I had no need of that hypothesis.” Of course, God can be still be used as a hypothesis for the existence of the universe. But because Newton had used a deficiency in scientific explanation as an argument for God’s existence, Laplace’s theory delivered an unnecessary blow to the apologetics of the time. Herein lies the danger: If gaps in scientific knowledge are used as arguments for the existence of God, what happens when science advances and closes those explanatory gaps?

Pointers to God: Fine-Tuning and the Moral Law

In the first and third chapters of The Language of God, Dr. Francis Collins mentions pointers to God that played a role in his journey to faith. One of these pointers is the fine-tuning of the universe. Fine-tuning refers to the way the basic laws of physics appear to be delicately balanced for life. This precision calls for an explanation that science cannot provide. There is a spirited debate over the meaning of fine-tuning, and some critics charge that invoking God as the fine-tuner is a return to the God-of-the-gaps. But there does not seem to be any way to explain the detailed properties of the laws of nature from within science. Fine-tuning arguments thus go beyond science into metaphysics to explain why the world that science studies has the properties that it does. Another pointer that Collins mentions, following C. S. Lewis, is the moral law. The moral law is an implicit and universal standard of ethics for humanity. Collins describes morality as a universal law, which, unlike laws such as gravity, is broken very often. Overall, the moral law is consistent with the type of behavior that is expected of products of evolution. However, as Collins points out, altruistic behavior often seems to go beyond what would be expected from the best-established processes of Darwinian evolution.³ Mathematical models developed by theorists like Martin Nowak ⁴ have established that natural selection can produce genes for altruism, but the radical self sacrifice of great saints like Mother Theresa of Calcutta seems to go beyond what the models can account for. A completely natural account of our origins may be insufficient to explain present observations of human behavior. However, if evolutionary psychology could explain human morality, or if theoretical physics could explain such perfect constants of nature, would theistic apologetics be discredited in any way?

Fine-Tuning

Unlike a God-of-the-gaps argument, the argument for fine-tuning uses science without divine action to reveal the impeccable precision of our Universe.⁵ Fine-tuning is described in terms of physical constants and the initial conditions of our universe. Fine-tuning does not try to draw attention to where science has failed, but rather emphasizes how science has revealed the intricate balance of the universe.

One might argue that science could potentially explain the origins of these delicately balanced features, but there are two important things to keep in mind. First, it is very unlikely that a scientific theory could explain away the improbabilities of our Universe without raising other improbabilities.⁶  Second, an argument for fine-tuning is unlike a God-of-the-gaps argument in that it is not intended to prove God’s existence. While it is true that the fine-tuning of the Universe adds credence to belief in a creator, such recent scientific findings could hardly be called upon as the basis or justification of the long history of theistic belief. While the fine-tuning of the Universe does indeed lead many people to consider the possibility of God’s existence, the fact that science cannot disprove God’s existence assures us that it also cannot prove it. Instead, fine-tuning can be understood as a feature of the universe that is accordant with belief in a creator. A deeper scientific explanation of these features — albeit highly unlikely — would not ruin its usefulness as a pointer to God.

Moral Law

The moral law also offers evidence that the world has evolved in a way that is consistent with the belief in a good and loving God. This remains true whether science eventually finds an account or explanation for morality. Even if a purely natural account of moral development could be found, the simple fact that morality has evolved is something that would be expected in a world created by a just and loving God.

Evolutionary theory explains selfishness in a most obvious and natural way. Altruism is far less obvious, but it can also be explained by recognizing that humans evolved in tribes that were essentially extended families with many genes in common. Imagine two tribes, one has genes to help each other even when it requires sacrifice and one does not have such genes. Which tribe will flourish? In such ways, genes for altruism can be selected by nature and spread in a population. But in its most radical form, altruism refers to situations where individuals risk their very lives to help someone they do not even know, and from whom a reciprocal benefit is unexpected or even unimaginable. This concept runs counter to the behavior expected from the best-established processes of evolution, and there are no widely accepted theories that can fully account for such examples. Some have suggested that radical altruism might perhaps be explained as misfiring —  we mistakenly go overboard in our desire to be nice. Radical altruism is currently somewhat mysterious.

As with most situations, science may someday provide an explanation for altruism. In light of that possibility, the argument from the moral law as a pointer to God is subject to the same risk of explanation as Newton’s God-of-the-gaps argument. If radically altruistic behavior is someday given a natural evolutionary explanation, it will no longer stand out as an inconsistency in evolutionary theory. However, Robert Wright argues in Non-Zero: The Logic of Human Destiny, that the evolution of altruism can be explained as an application of game theory.⁷ In Wright’s view, the deep mystery is not altruism itself, but the intriguing mathematical structures of the universe, like game theory, that can coax from the universe surprising behaviors like altruism.

Conclusion

If gaps in scientific knowledge are the basis for belief in God, then as science progresses, evidence for God’s existence continually diminishes. Fine-tuning does not rely on divine action as an explanation, but points out the striking precision of nature’s order in line with the requirements for human life, thus establishing a mysterious connection between physics and biology. As for the moral law, its use as a pointer to God can be understood in that human behavior has evolved in a way that is consistent with the idea of a good and loving creator. Belief in any moral truth rests upon the assumption of God’s existence or some other ultimate standard.

Finally, although these pointers to God should encourage one to consider God’s existence, they must not be placed at the foundation of faith. The belief in a creator and the experience of a relationship with God should not rest solely on a logical or scientific justification. But then, as Collins himself wondered, “How can such [religious] beliefs be possible for a scientist? Aren’t many claims of religion incompatible with the “Show me the data” attitude of someone devoted to the study of chemistry, physics, biology, or medicine?”⁸  

Astronomers and geologists have determined that the universe and Earth are billions of years old. This conclusion is not based on just one measurement or one calculation, but on many types of evidence. Here we will describe just two types of evidence for an old Earth and two types of evidence for an old universe; more types can be found under Further Reading. These methods are largely independent of each other, based on separate observations and arguments, yet all point to a history much longer than 10,000 years. As Christians, we believe that God created the world and that the world declares his glory, so we can’t ignore what nature is telling us about its history.

Age of the Earth from seasonal rings and layers

If you’ve ever seen a horizontal slice of a tree trunk, you’ve seen how a tree forms a new growth ring each year. In years of drought, the tree grows less quickly so the ring is narrower; in good growing seasons the ring is thicker. A tree’s age can be found by simply counting its rings. By comparing the pattern of thick and thin rings to weather records, scientists can verify that the method is accurate. This method can even be used on dead trees that fell in a forest long ago. For example, the last 200 rings in the dead tree might match up with 200 rings early in the life of the living tree, so the two trees together can count back many years. In this way, multiple trees can be used to build a master chronology for a forested region. European oak trees have been used to build a 12,000-year chronology.¹

The annual ice layers in glaciers provide a similar method that goes back much further in history. Each year, snowfall varies throughout the seasons and an annual layer is formed. Like the tree rings, this method can be verified by comparison to historical records for weather, as well as to records of volcanic eruptions around the globe that left thin dust layers on the glaciers. Scientists have drilled ice cores deep into glaciers and found ice that is 123,000 years old in Greenland² and 740,000 years old in Antarctica.³ These annual layers go back much farther than the 10,000 years advocated by the young earth creationists. The Earth must be at least 740,000 years old.

How can an old Earth be reconciled with Genesis? See Scripture Interpretation

Age of the Earth and solar system from radiometric dating

In your high school science classroom, you may have seen a large poster of the periodic table hanging on the wall. The periodic table shows the types of atoms that make up the world around us. An element in the periodic table can come in different flavors called isotopes. Some isotopes are unstable, and over time these isotopes “decay” into isotopes of other elements. For example, Potassium-40 is unstable and decays into Argon-40. As time passes, a rock will have more and more Argon-40 and less and less Potassium-40. Radiometric dating is possible because this decay occurs at a known rate, called the “half-life” of the radioactive element. The half-life is the time that it takes for half the radioactive sample to change from one element into the other.

Some isotopes have short half-lives of minutes or years, but Potassium-40 has a half-life of 1.3 billion years. Radiometric dating requires that one understand the initial ratio of the two elements in a given sample by some means. In this case, Argon-40 is a gas that easily bubbles out and escapes when it is produced in molten rock. Once the rock hardens, however, all the Argon-40 is trapped in the sample, giving us an accurate record of how much Potassium-40 has decayed since that time. So, if we find a rock with equal parts Potassium-40 and Argon-40, we know that half the Potassium-40 has decayed into Argon-40, and that the rock hardened 1.3 billion years ago.⁴

It’s hard to find rocks on the surface of the Earth that have not been altered over time. Most old rocks have been eroded by wind and water or submerged by continental plates. The oldest reliably dated rock formation is in Greenland, where several different isotopes were used to find an age of 3.6 billion years.⁵ Scientists also recently dated zircon grains (which resist erosion) in Western Australia to 4.4 billion years old.⁶ To find older rocks that haven’t been eroded, we need to look beyond Earth. Meteorites are rocks from the solar system that have fallen to Earth recently and haven’t suffered much erosion. Their pristine interiors give an age that dates back to their formation at the beginning of the solar system. Nearly all meteorites have the same radiometric age, 4.56 billion years old.⁷ Thus, the solar system, including the Earth, is about 4,560,000,000 years old.

Age of galaxies from the travel time of light

What about the ages of stars and galaxies, and the age of the whole universe? One way to measure these ages is with the travel time of light. Light travels incredibly fast – 300,000 kilometers per second, or 186,000 miles per second. On Earth, the delay due to light travel time is a tiny fraction of a second. But in space, the distances are so vast that the light takes a substantial amount of time to travel to us: 8.3 minutes from the Sun, 4.3 years from the nearest star, and about 8500 years from the center of the Milky Way galaxy. That delay means that we don’t see these objects as they are right now, but as they were when the light left. The universe actually works as a sort of “time machine,” in which we can see into the past simply by looking far away.

The calculation of the light travel time is simple once you know the speed of light and have a measurement of the distance. The speed of light is well known from experiments on Earth, and various astronomical observations confirm that the speed of light has not changed over the history of the universe. But measuring distances in astronomy is not trivial – you can’t just string a measuring tape from here to the center of the galaxy! Instead, astronomers use several interlocking methods to determine the distances, such as geometric calculations and brightness measurements. For example, some galaxies look much smaller and fainter than other galaxies of the same kind, showing they are much further away.⁸

The Andromeda galaxy, a near neighbor to our own Milky Way galaxy, is 2.3 million light years away. That is, we are seeing it as it was 2.3 million years ago. But that is just our local neighborhood. In recent decades, astronomers have detected galaxies located several billion light years away. If the light has been traveling billions of years to reach us, then the universe must be at least that old. This is completely independent of radiometric dating of the solar system, but both methods point to an age of billions of years, not thousands.

See Did God create everything recently but make it appear old?

Age of the universe from expansion

Not only can astronomers measure the distance of galaxies, they can measure how galaxies are moving. Galaxies are not holding still in space, nor are they moving randomly. Some galaxies are moving towards their neighbors, attracted by their mutual gravity. But the biggest pattern we see is that galaxies are moving apart from one another. This motion apart is not all at the same speed; instead it follows a pattern where galaxies that are further apart are moving more quickly.

This particular pattern indicates the whole universe is expanding. To see why, consider a loaf of raisin bread. The raisins are like galaxies and the dough is like the fabric of space in the universe. As the dough rises, it carries the raisins along, pulling them apart from each other. Raisins that started out on opposite sides of the loaf will be a few inches farther apart after the dough rises, while raisins that started out near each other may only move half an inch. So, the speed of their motion is proportional to the separation between them. In the same way, the space of the universe pulls galaxies further apart as the universe expands.

Astronomers detect a galaxy’s motion by looking at its light spectrum. When a galaxy is carried away by the expansion of space, its light waves are stretched out, making it appear redder. The change in the galaxy’s color is called the red shift, and can be used to calculate its velocity. From the measurements of many galaxies, astronomers can accurately measure the expansion rate of the universe as a whole.

The age of universe can be determined by imaging what the universe looked like in the past, “rewinding” the expansion. In the past the galaxies must have been closer together, and in the distant past they would have been packed together in a tiny point. If we assume that the expansion rate is constant over time, the age for the universe as a whole is about 10 billion years. However, astronomers have been working over the last 20 years to determine how the expansion rate changes with time. We now know that early in the universe the expansion was slowing down, but now it is speeding up. Using careful measurements of this change in expansion rate, the age of the universe is now known quite precisely to be 13.7±0.13 billion years. ⁹

Conclusion

Many different and complementary scientific measurements have established with near certainty that the universe and the Earth are billions of years old. Layers in glaciers show a history much longer than 10,000 years, and radiometric dating places the formation of the Earth at 4.5 billion years. Light from galaxies is reaching us billions of years after it left, and the expansion rate of the universe dates its age to 13.7 billion years. These are just a sampling of the types of evidence for the great age of the Earth and the universe; see the resources below for more.

Psalm 19 begins with the well-loved words “The heavens declare the glory of God, the skies proclaim the work of his hands.” Scientists often turn to this Psalm to express their praise to the Creator when they make discoveries in the lab – the biochemistry of a cell also declares the glory of God! In the second half of the Psalm, David turns his thoughts from the God’s world to God’s word, writing “The law of the Lord is perfect, reviving the soul.” David praises God for both revelations – for what God has revealed in both nature and scripture. In later centuries, theologians introduced the metaphor of two “books”¹ where nature is seen as a book, parallel to the book of Scripture. The Belgic Confession of 1561 states in Article 2 that

We know God by two means:

First, by the creation, preservation, and government of the universe,
since that universe is before our eyes like a beautiful book
    in which all creatures, great and small, are as letters
    to make us ponder the invisible things of God:
        God’s eternal power and divinity, as the apostle Paul says in Romans 1:20.
    All these things are enough to convict humans and to leave them without excuse.

Second, God makes himself known to us more clearly by his holy and divine Word,
    as much as we need in this life, for God’s glory and for our salvation.²

Since both are revelations from God, they both carry God’s full authority and cannot be ignored. The primary purpose of any revelation is to teach us about God,³ but both of these also have something to say about how and why God created the world. Sometimes the revelations appear to be in conflict, but since God speaks only truth, the two revelations cannot be teaching us contradictory things.

So what is the source of all the friction? The conflict must occur at the level of human interpretation: either a misunderstanding of what God is revealing in nature, or a misunderstanding of what God is revealing in scripture. In debates over Genesis and evolution, Christians often disagree about which interpretation is in error. We can agree, however, that scripture and nature are complementary and faithful witnesses to their common Author.

For more on the relationship between nature and scripture, see "What is the proper relationship between science and religion?"

Science: Interpreting God’s revelation in Nature

Building scientific theories resembles map making. A map gathers different kinds of data like longitude and latitude, elevations, waterways, and climate to make a coherent representation of reality. The map is not reality itself but a model of reality. Scientific maps of reality are known as “theories.” Some theories are new and tentative (like string theory), while others are long-standing and well-supported by abundant observations and experiments (like photosynthesis). The process of science is to develop and test these theories: scientists follow the map, see if it matches the real world, then modify the map to match reality better.

How reliable are scientific results? Science is a human activity, so of course it can be in error at times. Self-promoting individuals can push for outcomes that advance their reputation. A desire for particular results or an assumption about the ways things are can result in manipulation of data, whether consciously or unconsciously. Unfortunately, there have been plenty of examples of such contrived data in the history of science. One chronicle of how such distortions were perpetuated can be found in Steven Jay Gould’s The Mismeasure of Man,⁴ which retells the tragic story of how 19th century science found alleged data to support prevailing prejudices about the relationship between race and intelligence.

However, science is self-correcting. All scientific publications are peer-reviewed, where experts check for errors in methods, over-stated claims, and other problems. Published measurements are tested by other groups of scientists to see if they get the same results. Published theories are vigorously debated and compared to alternate explanations. Sometimes even selfish motivations can help the self-correcting process, since scientists can advance their careers by publishing errors and proposing new theories. Inaccuracies in theories are corrected when new discoveries and experiments reveal a problem. When theories are new and based on preliminary data, biases such as those described above can have a large influence on results. But after theories are tested and refined by many scientists all over the world, they give a reliable interpretation of physical reality.

Interpreting God’s revelation in Scripture

For Christians, the Bible is not just a book of moral lessons or factual statements. Rather, “All Scripture is God-breathed and is useful for teaching, rebuking, correcting, and training in righteousness, so that all God’s people may be thoroughly equipped for every good work” (2 Tim. 3:16-17). Scripture connects God’s action in real historical events with his purpose behind those actions. Scripture also draws us into the story, so that we are not mere readers, but citizens of God’s kingdom and part of God’s redemptive history. The Bible is the result of human-divine partnerships in which God inspired and commanded the human authors to communicate his word to his people.

Christians often disagree on the precise meaning of particular passages. Some scriptural teachings, like the accounts of Jesus’ death and resurrection, have clear meaning which has been affirmed by the church throughout the centuries and around the world. Other teachings, like baptism of adults vs. infants, are ambiguous and their interpretation has been debated for centuries. Some teachings, like ownership of slaves, were viewed one way for centuries, then were reinterpreted as the gospel moved into new cultures. Church tradition can be a valuable guide to good interpretation, but at times should be challenged.

How can we find the best interpretation of scripture? One good strategy is to always start by studying and pondering what the passage meant to the inspired human author and the original audience. The style of language, the genre of literature, and the historical and cultural context are all helpful in understanding the original meaning. Once we better understand God’s revelation to the first audience, we can consider what God might have to teach us today in the 21st century. Without this strategy, we risk imposing our own modern culture and personal preferences on the text. This does not mean you have to be a scholar to understand the Bible. Even in confusing passages (like Genesis 1-2), the primary teaching of scripture is usually clear even to a child (God created the world and declared it good). The careful background work becomes important for scholars and teachers who want to explore the subtle meanings and implications of the text (such as how it fits with science).

See "What factors should be considered in determining how to approach a passage of scripture?"

An Historical Example

The story of Galileo is a well-known historic example of conflict between science and Biblical interpretation. In Galileo’s time there was a heated disagreement over the solar system, specifically whether the Sun or the Earth was at the center. This led to a debate over the meaning of Bible verses like Psalm 93:1 which state “The earth is fixed and cannot be moved.” If this verse is read scientifically, it would mean that the Earth was stationary and did not orbit the Sun. However, Galileo made astronomical observations that showed the planets did move about the Sun. Today we understand Psalm 93:1 to mean that the earth is established and secure, just as God’s throne is established. Galileo, who remained a loyal Catholic to the end of his life, makes his position clear in a letter to the Grand Duchess Christina:

"[In] St. Augustine we read: 'If anyone shall set the authority of Holy Writ against clear and manifest reason, he who does this knows not what he has undertaken; for he opposes to the truth not the meaning of the Bible, which is beyond his comprehension, but rather his own interpretation, not what is in the Bible, but what he has found in himself and imagines to be there.' "

"This granted, and it being true that two truths cannot contradict one another, it is the function of expositors to seek out the true senses of scriptural texts. These will unquestionably accord with the physical conclusions which manifest sense and necessary demonstrations have previously made certain to us."⁵

Galileo did not see his discoveries as contrary to the Bible, but contrary to certain human interpretations of the Bible. And rather than dictating what the correct interpretation should be, Galileo recommended that Biblical scholars work to better understand the “true sense of scriptural texts.”

Interaction between science and biblical interpretation

What do we do when the results of science disagree with common biblical interpretations? One response is to say that the Bible is right and science is wrong; the Bible, after all, is more important to the Christian. This response, however, forgets that the Bible is always interpreted, and elevates a particular biblical interpretation to the authority of the Bible itself. It also discounts God’s revelation to us in the natural world, rather than listening to what science has learned about it.

Another response is to say that science is right and the Bible is wrong. This response, however, says that the Bible itself is in error, rather than that a particular interpretation is incorrect. It also elevates scientific knowledge as the best type of knowledge, even though science is ill-equipped to answer questions about ancient texts.

A better response is to reconsider the interpretations on both sides. When we hear a scientific result that seems to conflict with the Bible, we should look at it more closely. How strong is the evidence? Is there a consensus among scientists? Has the theory been tested extensively? What alternate theories are available? At the same time we take a closer look at Biblical interpretation. What did the passage mean to the original audience? What interpretations have been held throughout church history? What are the theological implications? Rather than rejecting one side or the other, we can study both more carefully, remembering that God is speaking to us in both scripture and nature. In this approach, science does not determine which interpretation of scripture is best. Instead, science motivates us to take a closer look at scripture, using good biblical scholarship to determine the best interpretation.

Occasionally, multiple interpretations of scripture seem equally appropriate when considered with the tools of biblical scholarship. In those cases, science can break the tie. By showing us what God reveals in nature, science can show that some interpretations are inappropriate. As Professor Donald Mackay writes:

Obviously a surface meaning of many passages could be tested, for example, against archaeological discoveries, and the meaning of others can be enriched by scientific and historical knowledge. But I want to suggest that the primary function of scientific enquiry in such fields is neither to verify nor to add to the inspired picture, but to help us in eliminating improper ways of reading it. To pursue the metaphor, I think the scientific data God gives us can sometimes serve as his way of warning us when we are standing too close to the picture, at the wrong angle, or with the wrong expectations, to be able to see the inspired pattern he means it to convey to us.⁶

What is a miracle? In the Bible, miracles, signs, and wonders are performed by prophets and apostles, by Jesus, and in answer to the prayers of God’s people. Biblical miracles are not merely for the amazement of onlookers, but serve God’s kingdom purposes. They always occur within a theological context.

Many atheists see science as explaining away or ruling out miracles. This idea goes back to the Scottish philosopher David Hume, who wrote:

A miracle is a violation of the laws of nature, and as a firm and unalterable experience has established these laws, the proof against a miracle, from the very nature of the fact, is as entire as any argument from experience can possibly be imagined.¹

Is Hume right? Do the “laws of nature” prove that miracles simply can’t happen? And if Christians accept mainstream science, must they also reject the miracles of the Bible? To address these questions, let’s first take a closer look at Biblical miracles.

This answer draws heavily from Ard Louis’ scholarly essay Science and Miracles, including several quoted paragraphs.

Two sorts of miracles

Miracles can be split into two types: those that are examples of providential timing (type 1 miracles) and those that can only be viewed as directly violating physical cause-effect relationships (type 2 miracles).

An example of a possible type 1 miracle would be the crossing of the river Jordan by the people of Israel:

Now the Jordan is at flood stage all during harvest. Yet as soon as the priests who carried the ark reached the Jordan and their feet touched the water's edge, the water from upstream stopped flowing. It piled up in a heap a great distance away, at a town called Adam in the vicinity of Zarethan, while the water flowing down to the Sea of the Arabah (the Salt Sea) was completely cut off. So the people crossed over opposite Jericho. - Joshua 3:15,16

Colin Humphreys, Cambridge professor of material science, has studied this miracle in great detail² and notes that the text supplies a number of unusual clues, including the fact that the water was blocked up a great distance away at a particular town. He has identified this with a location where the Jordan has been known to temporarily dam up when strong earthquakes cause mudslides (most recently in 1927). For many scientists, the fact that God is working through natural processes makes the miracle more palatable. R. Hooykaas writes

The scientist, even when he is a believer, is bound to try as far as possible to reduce miracles to regularities: the believer, even when he is a scientist, discovers miracles in the most familiar things.³

Of course this doesn’t take away from the fact that there was remarkable timing involved. Perhaps the attraction of this description comes in part because there is a direct corollary with the very common experience of “providential timing” of events, which believers attribute to God’s working.

There are also miracles in the Bible that defy description in terms of current science. Perhaps the most significant of these is the resurrection of Jesus Christ. If anything, science has strengthened the case for this not being a type 1 miracle. For example, in John 19:34 we read “Instead, one of the soldiers pierced Jesus' side with a spear, bringing a sudden flow of blood and water.” Modern medicine suggests that this is clear evidence that the pericardium, a membrane around the heart, was pierced, confirming that he was in fact dead. The more we know about the processes of decay that set in after death, the less likely it appears that Jesus could have risen from the dead by any natural means. Rather, science strengthens the case that if Jesus did indeed rise from the dead, the event must have occurred through a direct injection of supernatural power into the web of cause and effect that undergirds our physical world – it was a type 2 miracle. Of course the resurrection is central to Christian teaching. “And if Christ has not been raised, our preaching is useless and so is your faith” (I Corinthians 15:14).

Nature is what God does

Miracles happen against the backdrop of the regular day-to-day functioning of natural phenomena. The Bible describes not only miracles, but God’s routine action in the natural world. For example in Psalm 104, that great poem about nature, we read, “He makes springs pour water into the ravines, it flows between the mountains" (Psalm 104:10). The first part of this verse refers to God’s direct action while the second part suggests that water flows through its own natural properties. Read the Psalm for yourself and notice how the point of view changes fluidly back and forth between what we might call the laws of nature and the direct action of God. Such dual descriptions can be found throughout the Bible.

The New Testament is even more explicit. “The Son is the radiance of God's glory and the exact representation of his being, sustaining all things by his powerful word” (Hebrews 1:3). “He is before all things, and in him all things hold together” (Col 1:17). In other words, if God were to stop sustaining all things by his powerful word, the world would stop existing. That is why, when describing nature, the Bible so easily switches perspectives depending on whether it is emphasizing the regular behavior of natural phenomena, or their origin in God’s providential sustenance. So, as St. Augustine might say, “Nature is what God does.”⁴

As Christian thinkers throughout the Middle Ages wrestled with the questions of miracles and God’s action in the world, the following ideas emerged: if the regularities of nature are a manifestation of the sustenance of God then one would expect them to be trustworthy and consistent, rather than capricious. The regular behavior of nature could be viewed as the “customs of the Creator” as it were. Christians glorify God by studying these “laws of nature.” A strong case can be made that such theological realizations helped pave the way for the rise of modern science.⁵

By the time the Royal Society of London, the world’s first scientific society, was founded in 1660, Christian thinkers like the metaphysical poet John Donne, then dean of St. Paul’s Cathedral in London, could write “the ordinary things in Nature, would be greater miracles than the extraordinary, which we admire most, if they were done but once... only the daily doing takes off the admiration.”⁶

Miracles and Science

So, do natural laws prevent miracles? No. From a Christian perspective, natural laws do not, and cannot, limit God. Natural laws are merely human descriptions of God’s regular activity in nature. Since God is the creator and sustainer of all physical laws, he clearly has the freedom and ability to suspend those laws when he wishes. Miracles are simply cases where God chooses to work outside his usual patterns.

Can a scientific explanation of a miracle explain it away? No. As we saw above, some miracles (type 1) already have scientific explanations; they are rare but possible events that occur with significant timing. Consider 1 Kings 18, where Elijah prays for rain after a long drought. As he prays, his servant sees a small cloud form over the Mediterranean, which soon grows into a heavy rainstorm. Even in pre-scientific times, rainstorms were considered a normal part of the world, not a miracle. Yet the timing of this rainstorm after a long drought was a clear response to Elijah’s prayer; the precise timing and the theological context make it a miracle. Since type 1 miracles can already be explained scientifically, it is not distressing when a scientist finds an explanation that moves a type 2 miracle to type 1. This does not reduce the mircale’s spiritual significance to the original audience, or imply that God was less active in the miracle.

Miracles and evolutionary creation

Is there room in evolutionary creation to believe in miracles? Yes. Evolutionary creationists, like all Christians, accept the miraculous incarnation and resurrection of Jesus Christ. They believe that the Biblical miracles happened and that God can do miracles today. Like other Christians, they may debate whether certain Biblical miracles were type 1 or type 2, but this is not an attempt to explain away God’s involvement in the miracle.

This acceptance of miracles can be shocking to non-believing scientists, many of whom view miracles as superstitious or primitive beliefs. Some atheists view science itself as a savoir, the hero who rescues society from irrational ideas and harmful superstitions like miracles. Rudolph Bultmann, a man famous for his attempts to de-mythologize the New Testament, wrote in 1961 “It is impossible to use electric light and the wireless and to avail ourselves of modern medical and surgical discoveries, and at the same time to believe in the New Testament world of spirits and miracles.”⁷ By getting rid of the miracle stories in the Bible, Bultmann and his followers hoped to make the Christian story more palatable to modern society. This attitude, however, puts natural law above God, rather than accepting that the Creator can choose to suspend the natural laws he made. Moreover, demythologizing the Bible is inconsistent with the heart of Christianity. The central Christian belief is a stunning type 2 miracle: the resurrection of Jesus from the dead. If one grants the basic Christian premises that God governs the natural world and that Jesus rose from the dead, then miracles are not surprising at all. The Cambridge evolutionary biologist Simon Conway Morris notes: “I am not surprised at those [NT miracles] reported, I am surprised that they are so few. What else would you expect when the Creator visits his Creation?”⁸

Evolutionary creationists differ with other Christians on the question of whether God performed miracles in natural history. Christians agree that God did miracles in human history, but natural history is different. Young Earth Creationists see God creating the earth and life in 6 days through a string of type 2 miracles. Supporters of Intelligent Design see evidence that natural laws are not enough to explain the development of life today. Evolutionary creationists, however, see God creating using regular patterns that can be described scientifically. This is not from a distrust of miracles. Some evolutionary creationists argue that the context of natural history is simply not appropriate for a miracle: since there were no people living millions of years ago, much of the theological purpose of signs and wonders is lost. Other evolutionary creationists are comfortable in principle with God creating species through type 2 miracles, but they simply don’t see scientific evidence for it. The evidence points to a God who chose to use regular chains of cause and effect to bring about life.

See "What role could God have in evolution?"

Are miracles in natural history necessary to display God’s glory? No. God’s glory is abundantly displayed through processes we understand scientifically, from the intricacy of a cell to the beauty of a star cluster. Our wonder is not diminished by scientific explanations; instead, science gives us a glimpse of how God works. In fact, the very regularity of the natural world is a testimony to God’s faithfulness. In Jeremiah 33, God specifically invites us to look at the regular patterns of nature, “the fixed laws of heaven and earth” (Jer 33:25), as an example of how he will be faithful in his promises. God’s glory does not just appear in miracles. Evolutionary creationists encourage all Christians to celebrate God’s actions through natural law as full displays of his “eternal power and divine nature” (Romans 1:20).

The science of evolution is compatible with many faith traditions. Muslims, Jews and Christians alike can align their faith with the scientific account of our origins, and there is no way to give a scientific proof for one monotheistic faith over another. Therefore, instead of arguing that science supports Christianity over other faiths, this response will simply show the compatibility of Christianity with a scientific understanding of the universe. The Bible’s description of God is consistent with what is seen in the world around us.

See “What is the proper relationship between science and religion?”

Consistency

Christian doctrine is broadly compatible with the scientific accounts of our origins. The Genesis creation story, for example, speaks of beginnings in a way that reminds us of the Big Bang theory, although this concept would certainly not have been a part of the author’s worldview.

Science shows us a universe that reflects many of the Christian God’s characteristics, such as omnipotence, love and perfection.¹ For example, God’s omnipotence and perfection are evident through the laws of nature, all of which are finely tuned to allow life to develop. From a scientific standpoint, these features of the universe are surprising and warrant further explanation. But in light of the Christian narrative — in which a rational God intentionally created a universe congenial to life — the fine tuning of the universe makes sense. The Bible also claims that human beings have been created in God’s image.² Our ability to love others and engage in meaningful relationships is therefore consistent with the existence of a loving God. And although radical altruism challenges evolutionary explanation, it resonates nicely with Christianity. Why, for example, would Mother Theresa of Calcutta spend her life with the poor? Why would a soldier sacrifice his life for people he does not know? These examples fit comfortably within the story of a God who sacrificed his own life for his creation, and whose image we bear.

Consider the words of Albert Einstein: “The eternal mystery of the world is its comprehensibility.”³ The simple fact that we have the intellect and skills to inquire and test and make scientific discoveries is remarkable. But with a rational, all powerful God in whose image we are made, it is no surprise that we are able and eager to make scientific sense of the world around us. Oxford University professor Alister McGrath puts it well:

"The Christian vision of reality offers us a standpoint from which we may view the natural world, and see certain things that others might indeed regard as puzzling, or strange — such as fine-tuning — as consonant with the greater picture that the Christian has to offer."⁴

Many of the underlying themes of the monotheistic traditions are shared. Benevolence and justice, for example, are valued in many faiths. The central difference between Christianity and other faiths is the purpose and meaning of Jesus Christ’s life and the truth of his resurrection. There is nothing about evolutionary science that conflicts with the central Christian trinitarian understanding of Jesus.

Rationality

Read Darrel Falk's essay A Rational Belief for more on why Christian faith can have a rational basis.

Though belief in the Christian God is not scientifically provable, it is not irrational. Commitment to Christ is a reasonable choice supported by a variety of non-scientific evidence from history, philosophy, and the testimony of others. Ultimately, the Holy Spirit works in each person’s life to bring them into relationship with Jesus.

The existence of God is an enduring and popular philosophical problem. Many arguments claiming to prove the existence of God have been proposed througout the centuries, often on the basis of some feature of the natural world. There have also been attempts to disprove the existence of God, which is a more complex task. Consider how much easier it is to establish that there is a black swan somewhere on the Earth compared to establishing that there isn’t one. G.K. Chesterton made this point: “Atheism is the most daring of all dogmas, for it is the assertion of a universal negative.”¹

Popular arguments for the existence of God include the cosmological argument, the ontological argument, the moral law argument, and the argument from Design. The argument from Design is a more general version of the narrower perspective about irreducible complexity that forms the core of the Intelligent Design movement. Each of these arguments supports a certain belief in a creator. The response to many of these arguments, however, is: 

“If God created the world, what created God?”

This is a reply that requires serious consideration. It suggests that certain arguments for God’s existence only push the question of beginnings one step farther back. It also suggests that any God complex enough to account for all of creation would necessarily be complex enough to require an explanation.  Richard Dawkins is one of the strongest proponents of this argument.

An Answer From Doctrine?

In many faiths, God’s origin is straightforward. Christian doctrine teaches that God is eternal and thus had no beginning. The Psalms speak clearly about God’s eternal nature, affirming, but never defending God’s existence:

“Before the mountains were born or you gave birth to the earth and the world, even from everlasting to everlasting, you are God.” ²

“For a thousand years in Your sight are like yesterday when it passes by, or as a watch in the night.” ³

These verses, and many others like them, highlight the complexity of God’s relation to time. Theologians have debated the relationship of God to time for centuries and no doubt will continue to do so. It is a question that we probably cannot answer. In one thoughtful response, God is the creator of time itself, and thus exists outside of time seeing all of history at once. Verses like those above are often used to support this view. On the other hand, this view is often critiqued by Biblical scholars including Clarke Pinnock, John Sanders and Gregory Boyd⁴, who point out that God is portrayed in scripture as acting in time. For example, when God is negotiating the fate of Sodom and Gomorrah with Abraham (Genesis 18), or lamenting having created humans at the time of Noah (Genesis 6:5-8), God certainly seems to be in time and responding to the unfolding course of events. But of course, given the difficulty our time-limited minds have in grasping this philosophical problem, there is no compelling reason that God could not be both outside of time and capable of acting within it.

An Answer From Definition?

Answers from religious doctrine are rarely adequate for nonbelievers. In fact, many fervent believers in God reject the argument about God’s timelessness because even timeless beings need explanations for their existence. But if God is the creator of all things, and yet also requires cause, we face an infinite regress of causes. The only way to avoid this infinite regress problem is to state — as Christian theology has always done — that God is the first cause and is entirely self existent, meaning the reason for God’s existence is contained within the very definition of God.

While this viewpoint certainly may be attractive, it still fails to convince skeptics who are more likely to favor the idea that the universe contains within itself the reason for its own existence. If that could be true of God, why couldn’t it be true of the universe? There is certainly reason to be skeptical about the common sense intuition that everything must have a cause or that everything must have a reason to be as it is. This perennial assumption has been challenged by the physics of the 20th century that uncovered a mysterious quantum world where things often do not appear to have reason to be the way they are.

The common sense assumption that everything must have a cause or a reason to be as it is also suffers from what is called the fallacy of composition. This fallacy comes about when we assume that properties of the parts apply to the whole. For example, just because every member of the human race has a mother, we cannot infer that the human race itself has a mother. Similarly, a collection of spherical things would not itself have to be spherical. In discussions about the origins of the universe, we would say that just because every individual part of the universe has a cause, that does not mean that the entire universe has a cause.

The realization that our universe had some sort of beginning has opened up exciting new conversations about origins. In some ways, a universe with a beginning seems to beg for a cause. But if the universe came into being from nothing , it becomes deeply problematic to speak of anything having caused the universe to exist. Some cosmologists would argue that our universe is the result of an uncaused quantum fluctuation. Such fluctuations do not have causes in the traditional sense, so they argue this does away with our universe needing a cause. But there is a significant problem that  the vacuum that fluctuates is not nothing. Quantum vacuums — which are what you get when you remove from space all the particles and energy — are real. They have activity, laws and rules. Our universe may have fluctuated into existence from such a vacuum, but the vacuum remains unexplained.

Cosmologist Lee Smolin suggests in Life of the Cosmos, that black holes can give birth to new universes.⁵ He proposes that our present universe emerged out of a black hole in some other “meta-universe.” And perhaps our universe is presently birthing new universes. Such a process, while clearly speculative, provides a caution against extrapolating from common sense notions of causality to philosophical conclusions about the nature of all of reality.

An Answer From Plausibility

The difference between the theist and atheist positions on this topic is that by assuming that everything — including the universe — has to have a cause, then the atheist is left with a dilemma of what or who that first cause might have been. For the theist, the answer is God, but a satisfactory reason must be found why God should be exempt for the need for a cause. Such a response is available through the Augustinian concept that God is not limited in space and time, and  therefore the argument of needing a first cause loses its power.

On the other hand, if not everything needs to have a cause, the theist and atheist have no grounds for arguing this part of their case.

But the argument can be reframed in a way that is more sensitive to postmodern intuitions about causation and the importance of starting points. Suppose as a religious believer you ask the question, “What kind of a universe is most compatible with my belief in an eternal God?” In this case the response affirms but does not prove the reality of God. The universe that we experience appears to have had a beginning; it appears to be finely tuned for life; it appears to have a place for love and purpose. These appearances affirm as plausible your prior belief in God.

See "What is the 'fine-tuning' of the universe, and how does it serve as a 'pointer to God'?"

 

Now suppose you start from the atheist assumption. In this case the universe must not really be as it appears. It cannot have a real beginning, be tuned for life and love, and purpose can’t be anything other than illusory epiphenomena — the curious byproducts of chemistry and physics. The whole picture has a claustrophobic bleakness.

Bertrand Russell, one of the most brilliant and ruthlessly honest atheists of the 20th century, captured this sense of despair in A Free Man’s Worship:

“That man is the product of causes which had no prevision of the end they were achieving; that his origin, his growth, his hopes and fears, his loves and his beliefs, are but the outcome of accidental collocations of atoms; that no fire, no heroism, no intensity of thought and feeling, can preserve an individual life beyond the grave; that all the labors of the ages, all the devotion, all the inspiration, all the noonday brightness of human genius, are destined to extinction in the vast death of the solar system, and that the whole temple of man's achievement must inevitably be buried beneath the debris of a universe in ruins – all these things, if not quite beyond dispute, are yet so nearly certain that no philosophy which rejects them can hope to stand. Only within the scaffolding of these truths, only on the firm foundation of unyielding despair, can the soul's salvation henceforth be safely built.“ ⁶

In contrast to this view, the theist can affirm that the wonders encountered in the world are real, that they belong, and are a reflection of the glory of the creator whose mysterious power upholds everything.

Conclusion

The world disclosed by modern science is far subtler and nuanced than the world in which philosophers and theologians have lived for the past few centuries while formulating their arguments about the mysterious relationship between God, the physical world, time and causality. Nevertheless, no development in contemporary science poses a particular challenge to the view that God is creator. And some developments, like the discovery of fine-tuning in the physical laws, are supportive of traditional affirmations. The common-sense assumptions that have historically undergirded this entire discussion, however, need reconsideration in the face of recent scientific developments. We must be intellectually humble in making claims about God as creator. But we can also state confidently that denials that God is creator are fraught with even more unresolvable difficulties and ultimately provide a far less satisfactory grounding for a worldview in which meaning and purpose play important roles.

Many voices today say that science and Christianity are opposed to each other. Some atheists claim that science has debunked religion and superstition of all forms. Many in the general public think that the church is anti-science. And within the church, science is often portrayed as challenging important Christian beliefs. None of these voices, however, hint at the positive and fruitful relationship between Christianity and science. Here we review several ways to view the relationship between science and Christianity.

Are Christianity and science at war?

When creation and evolution clash in a courtroom, the daily news fills up with stories suggesting that there is some profound conflict between science and Christianity. Inevitably, someone mentions the historical incident of Galileo. Galileo was charged with heresy by the church in 1633 for teaching that the Earth orbits the Sun. From Galileo to textbook battles, the hasty conclusion is that science and Christianity are engaged in an endless debate, fundamentally opposed to each other.

For a review of Galileo and other historic interactions between science and Christianity, see “Christianity and Science in Historical Perspective” by Ted Davis (blog series, PDF) and “The Galileo Affair: Emblematic or Exceptional?” by Matt Rosano (blog)

Yet the Galileo incident and today’s conflicts are often about much more than the particular claims of science or faith. Personalities, politics, and culture wars all come into play when drawing the battle lines. In many instances, science and scientists are not themselves in conflict with Christian belief. In fact, Galileo himself was a Christian who believed “that the glory and greatness of Almighty God are marvelously discerned in all His works and divinely read in the open book of Heaven”¹ Many scientists then and now² are Christians who see no conflict between their scientific work and their faith. Most things studied via the natural sciences—such as the migration patterns of birds or the interior of atoms—do not raise any theological or Biblical concerns.

The “warfare” model, then, is not very helpful for understanding evolution and Christianity, since it assumes conflict from the start. A few particular areas of scientific study—like the big bang and evolution—do raise concerns for Christians, but most of the BioLogos website (see Questions by Category on the right) is devoted to showing that evolution and Christianity are not truly at war. In the rest of this answer, we’ll explore other models for the working relationship between science and Christianity.

Mark Noll, a leading historian and evangelical, gives 16 reasons why the warfare model is a mistake. (blog series)

Are Christianity and science completely separate?

One way to erase the conflicts between science and Christianity is to view them as entirely separate endeavors, with different purposes, methods, and bodies of knowledge. This view emphasizes that science is a system of knowledge about the world and its behavior, whereas religion is about morality, God, and the afterlife. Thus, Christianity and science cannot conflict, because they are addressing different sorts of questions.³

This model has some weaknesses (see below), but it does help us understand some important aspects of the relationship. Many apparent conflicts between science and religion occur because of a lack of understanding of the fundamental differences between the two. When someone claims that the Bible answers a scientific question, and another claims that science answers a question about God, the conflict immediately flares up. Many conflicts become enflamed because participants forget that Christianity and science do generally address very different questions.

This model also reminds us that science is not the only source of knowledge. There are many sorts of questions that simply do not fall under the domain of science. Borrowing an example from the Rev. John Polkinghorne, there is more than one answer to the question of “Why is the water boiling in the tea kettle?”⁴ The scientific answer might be “the water is boiling because at this temperature it undergoes a phase transition from liquid to vapor.” Another acceptable, though nonscientific, answer is “the water is boiling because I put the kettle on the stove.” A third answer might be “the water is boiling because my prayer partner is coming over for tea.” None of the answers is wrong; rather, each gives a different perspective on the question. The scientific answer does not tell the whole story. Science cannot answer questions like “Is my friend trustworthy?” or “Is this poem well written?” Science is tremendously successful in understanding the physical world, but we should let that tempt us to think it can be used to understanding everything in life.

Artist Mark Sprinkle writes on the importance of music and poetry in understanding God’s world.

Science cannot answer the question “Does God exist?” Some people argue that God’s existence is actually a scientific claim that could be tested like a chemical reaction. But science studies the natural world, not the supernatural. No amount of scientific testing or theorizing could prove or disprove the existence of a supernatural creator. The claim that “God exists” is a metaphysical one, not a claim about nature or physical laws

Though science cannot prove or disprove God’s existence, it can provide clues that support belief in God. See “What is the fine-tuning of the universe?” and “On what grounds can one claim that the Christian God is the creator?”

This model also reminds us that the Bible is not the only source of knowledge. The Bible is silent on most of the topics that concern scientists, like protons, photosynthesis, penguins, and Pluto. The Bible is not a science textbook, in the same way that it is not a textbook of plumbing, agriculture, or economics. Instead, God teaches us about these things through his general revelation in the created order.

However, this model has some significant weaknesses. It isolates religion from science, which can be a first step in marginalizing religion from public discourse. By defining religion and science as separate, this model doesn’t help us understand the interactions they do have, either negative or positive. The model also sets science on its own, apart from religion, while Christians believe that no part of our lives is outside of our walk with God.

Science and Christianity interact, correcting and enhancing each other

While many questions can be clearly categorized as “science” questions or as “Bible” questions, other questions are on the boundary. For topics like evolution, medical ethics, and climate change, we need to consider both science and faith when seeking out God’s truth. For such complex questions, we need all the knowledge and wisdom we can get, rather than handicapping ourselves by looking only to science or only to the Bible. If we look to only one or the other, we will get a distorted view of the issue. As Pope John Paul II wrote,

Science can purify religion from error and superstition; religion can purify science from idolatry and false absolutes. Each can draw the other into a wider world, a world in which both can flourish.⁵

God reveals himself in the book of Scripture and the book of Nature. To learn more about God and his work, we study both books. When one book is confusing or ambiguous, insights from the other book can help us understand it. In both revelations, we look for the underlying truth of who God is and how he made the world. Rev John Polkinghorne wrote, “Science and theology have things to say to each other, since both are concerned with the search for truth attained through motivated belief.”⁶

For more on God’s two revelations, see “Can Science and Scripture Be Reconciled?”

Faith can have a positive impact on science by guiding the practical application of scientific discoveries. With the rapid advance of science and technology, many ethical questions are facing our society. Development of safe nuclear energy is not far from the development of nuclear weapons, new medical imaging techniques save lives but are too expensive for the poor, and DNA testing improves treatment of genetic disorders at the risk of the results being misused.⁷ To address these complex questions, we need both science and the moral grounding of religion. We can’t just give a quick answer from the Bible without studying the scientific complexities, nor can we look to science alone to guide ethical decisions. Christianity and other religions lay the groundwork for the moral standards that are essential for the appropriate use of science and technology.

Science also has a positive impact on the faith of the believer. The Bible teaches that “The heavens declare the glory of God” (Psalm 19:1). Christians see God’s glory when looking up at the stars, and in colliding galaxies seen through a telescope. God’s glory is revealed in the beautiful symmetry of a maple leaf, and in the complex biochemical activity inside each cell in that leaf. Science and technology have shown us much more of God’s creation than was known in Biblical times, revealing more and more of God’s glory.

See “Science as an Instrument of Worship” by Jennifer Wiseman (PDF) (blog series)

Finally, Christianity can provide the belief framework for how and why we do science. Christians need not set aside their faith when they sit down to do science. Read on to the next question for more.

Organisms have changed significantly over time. In rocks more than 1 billion years old, only fossils of single-celled organisms are found. Moving to rocks that are about 550 million years old, fossils of simple, multicellular animals can be found. At 500 million years ago, ancient fish without jawbones surface; and at 400 million years ago, fish with jaws are found. Gradually, new animals appear: amphibians at 350 million years ago, reptiles at 300 million years ago, mammals at 230 million years ago, and birds at 150 million years ago.¹ As the rocks become more and more recent, the fossils look increasingly like the animals we observe today.

The Transition to Land: Sea Creatures to Land Animals

Fossils of land animals, or tetrapods, first appear in rocks that are about 370 million years old. In older rocks, only sea creatures are found. But in 1998, scientists found a fossilized fin, 370 million years old, with eight digits similar to the five fingers humans have on their hands, as shown in Figure 1. However, the fin was undoubtedly that of a fish, which means this fossil is strong evidence of a transitional form.

Figure 1:An Illustration of the fossilized fin found in 1998. Its resemblance to a tetrapod is an indication of gradual evolutionary change from sea creatures to land animals. Source: Image is used by permission from Falk, Coming to Peace, 113.

One of the great success stories in the examination of the fossil record was the finding of a near-perfect fossilized transition between a vertebrate adapted for water and one adapted for land. Evolutionary biologist Neal Shubin set out to find a more complete transitional specimen than the 1998 fin. He determined the exact age of rock that he expected would yield a transitional land/water animal, and then he and his team spent four summers in the Arctic scouring rocks of that age to find one. The results (see Figure 2 below) were spectacular.²

From Reptiles to Mammals

Mammals first appeared in the fossil record about 230 million years ago, nearly 70 million years after reptiles first appeared. One group of reptiles, the cynodonts, first appeared about 260 million years ago and became increasingly mammal-like in more recent fossils—circa 245 million years ago. This change can be seen most clearly in the bone structure of the ear, as illustrated in Figure 3.

Figure 3: As shown in the image above, transitional fossils of cynodonts had two jaw hinges. These fossils date from a time when the dentary and squamosal bones were beginning to take over the role of jaw hinge (hinge #2). This allowed the articular and quadrate bones to evolve into the second and third bones of the mammalian ear, as shown on the right. Source: Image used by permission from Falk, Coming to Peace, 119. Originally from F. H. Pough, J. B. Heiser, and W. N. McFarland, Vertebrate Life, 4th ed. (Upper Saddle River, NJ: Prentice Hall, 1996), 607.

Scientists found a species of cynodonts, dating to just before the emergence of mammals, that had a double jaw hinge like that of a mammal. A pair of bones found in even earlier cynodont fossils seems to have transitioned slowly into the ear. No other fossils have been found that share a similar structure to the transitional cynodonts and date back before the time of mammals. Likewise, soon after mammals appeared, these cynodonts became extinct. This timing implies that the cynodont fossils record the transition from reptiles to mammals.³

Transitional Forms: Few and Far Between

Transitional forms occur just when one might expect to see a change from one body type to another. However, a common objection is that few transitional fossils have been discovered; thus many lineages cannot be traced smoothly.

There are several reason for these gaps in the fossil record. First, fossilization is a very rare event. Plus, transitional species tend to appear in small populations, where rapid changes in the environment can provide a stronger evolutionary drive. Finally, because fossilization itself is a rare event, smaller populations are sure to produce fewer fossils. The fact that transitional species have been found at all is remarkable, and it offers further support of gradual, evolutionary change.