So what is the real relationship between science and religion? Bitter rivals or teammates? Adversaries or advocates? The truth and the lie? The media would have you believe that there is an immense chasm between science and religion, with no possibility of overlap or complementarity. As would others who are polarized about the topic, like atheists Richard Dawkins and Christopher Hitchens and fundamentalists Ken Ham and Kent Hovind. But this line of thinking comes from a basic misunderstanding of both God and reason.
The clearest and most direct formal expression of the relationship between faith and science that I have found is expounded upon in the Catechism of the Catholic Church, paragraph 159:
Faith and science: "Though faith is above reason, there can never be any real discrepancy between faith and reason. Since the same God who reveals mysteries and infuses faith has bestowed the light of reason on the human mind, God cannot deny Himself, nor can truth contradict truth […] Consequently, methodical research in all branches of knowledge, provided it is carried out in a truly scientific manner and does not override moral laws, can never conflict with the faith, because the things of the world and the things of faith derive from the same God. The humble and persevering investigator of the secrets of nature is being led, as it were, by the hand of God in spite of himself, for it is God, the conserver of all things, who made them what they are."
Divine revelation comes in two forms: the Word of God (including both Sacred Scripture and Sacred Tradition) and the Work of God (including the natural, physical world and the laws that govern it). Both are equally valid forms of truth, as they stem from the same Source. And since truth can never contradict truth, a truth revealed in one cannot ever be in conflict with a truth revealed in the other. Once this is fundamentally understood, fear about science overthrowing religion becomes obsolete, and science has a moral compass guiding discovery and innovation.
In the Gospel of Mark, Jesus says "Is a lamp brought in to be placed under a bushel basket or under a bed, and not to be placed on a lampstand? For there is nothing hidden except to be made visible; nothing is secret except to come to light. Anyone who has ears to hear ought to hear." (Mark 4:21-23). What does Jesus mean in this passage?
For me, as a scientist, this passage has always had a special meaning. Science is all about bringing what is hidden in the natural world (the natural laws) into the light of human knowledge and reason. In effect, it is a lamp that shines its light and reveals the Work of God. So what does Jesus say about such lamps, then? Not to place them in places where their light won't shine. Science reveals His creation. He wants it exposed.
The same holds true, of course, to that which shines its light and reveals the Word of God: His Church. It is the Church that provides important guidance as to the meaning of Scripture, objective truths unknowable by reason alone (like the mystery of the Trinity, for example), and moral certitude despite winds of change in cultural attitude and behavior.
Both science and the Church are equally aided by the gift of reason. Rational arguments are just as necessary in theological questions as in scientific ones. And it is reason that leads us to the conclusion that we need both science (for our physical concerns) and religion (for our spiritual concerns) in our life tool belts to deal with the problems that arise from being creatures consisting of mind, soul, and matter.
Putting this all together, then, we can see that science and religion are never really completely divorced from one another, but rather serve complementary roles. Science, guided in the moral spirit of the Church, provides us with answers to "how?" questions: How does gravity work? How does a baby progress from a zygote to a fetus? How can we better improve the quality of human life? As noted in one of the Spiderman movies, "With great power comes great responsibility." Such is the case especially with science. Science is an incredibly powerful tool, but if that power is left to its own devices without a moral compass, it is an evil, fatal, and disastrous weapon that advances the most horrific violations to human dignity and worth (see modern China, eugenics, Nazi Germany, Joseph Stalin, Pol Pot, Mao Tse-Tung for a few examples).
Religion, on the other hand, aided by scientific and historical evidence, is able to provide us with the answers to our existential "why?" questions: Why am I here? Why is there something rather than nothing? Like science, religion without a rational basis can also be an extremely dangerous weapon primed for atrocities (see 9/11, David Koresh, and the Heaven’s Gate cult, for example).
Used in their appropriate roles, science and religion give us the complete set of tools for understanding and interpreting the Work and Word of God. If we accept science, yet neglect religion, we miss out on a full volume of God's two-part revelation (including the person of Jesus Christ)! We are brains without a heart. If we accept religion, and reject science, then we likewise miss out on a full volume of God's revelation, and are hearts without a brain. Both scenarios are equally despicable.
God gave us reason, and God gave us faith. Both are gifts. Both are to be used in their maximum capacity. Thank God for science and religion, so that we can have our heart and brain working in unison in comprehending His revelation in the fullest way that we can, at least on this side of heaven!