In this brief video Conversation, Os Guinness addresses the problem of holding a purely naturalistic worldview—one that does not coincide with many basic human concepts.
For example, Guinness notes that there are certain things very important to human beings including freedom, justice, purpose in the universe, moral intuition, and altruism, which are either nonexistent or else devalued when viewed through a naturalistic lens.
When these things are filtered through the lens of a Judeo-Christian perspective, however, they make sense. One is able to recognize that regardless of individual circumstance (physical limitations, poverty, etc.) all people made in the image of God have a precious dignity.
The naturalists cannot say the same—so there is a bleakness to their dogma that we do not see with Christianity.