For some Christians, evolution would, if true, completely shatter the doctrine of Original Sin. After all, if humans evolved, then there wasn’t an Adam, there wasn’t a Garden of Eden, and there wasn’t a Tree of Knowledge of Good and Evil. If that’s the case, these Christians believe, then there wasn’t a Fall and there wasn’t a reason for Christ to be crucified. Thus, in their minds, evolution is completely incompatible with Christian teachings.
For me, “original sin” is a way of offering a pre-neurological explanation for selfish, reactive behaviour. I therefore think that the most ardent religious extramists (of any religion, or any ideology for that matter) are actually the embodiment of that which they purport to stand against. This isn’t reason to fight or ostracize them, though, but an opportunity to share the spark of understanding. Sin, the Tree of Knowledge, Adam and the expulsion from Eden are all metaphors for the development of individual and social consciousness.
Does that make you feel uncomfortable? Then you see my point exactly. Answers are challenging, they force us to re-evaluate and to grow. The truth was never handed to us – it’s up to us to discover it.