What I see in a lot of creationism/evolution debates is creationists defending the literal truth of Biblical stories, and evolutionists showing them how these stories cannot be literally true. In my opinion that's fair enough from a scientific point of view, but I think some crucial elements are being missed.

Many religious stories incorporate themes and imagery which have been repeated since time immemorial. They seem to be part of our collective unconscious. They connect with that part of us and make us think about what it is to be human, living in this world. The literalist does not appreciate the stories on this level, and an atheist would simply see them as stories which are not true -- fantasies. If you look at the Adam and Eve story though, you have things like the tree of life and the serpent -- themes which are also echoed in many other stories from other cultures. There's this idea that humans can become gods by eating fruit from the tree, but this was not meant to be. The serpent can represent many different things: eternity, evil, knowledge.

In my opinion, the authors of stories like this wanted them to resonate with people in this way. Taking them literally is like believing that Jesus' parables have to be factual histories, when in fact their historical accuracy is irrelevant to the point being made.