This has been hinted at by several postings, but there are a couple of serious consequences.
1) If evolution is true, most likely Genesis 1 - 3 are not historical. There are various arguments about how a day may be an age, but in fact most people who accept evolution take Gen 1 - 3 at face value, and think they’re wrong, at least as history. But the moment you accept that the Bible may be wrong, there are other questions: Modern archaeologists generally don’t think anything before maybe the time of the kings is accurate. In specific, the Exodus as described didn’t happen. In fact the current understanding is that the people who became Israel largely originated in the hill country in Palestine, and moved into the cities slowly and mostly without major conflict. Once you start thinking that the Bible might be a human book describing God’s interactions with us from our perspective, anything in it might be wrong.
That is very troubling to many people. It seems safer to hold the line, and claim that the whole Bible is accurate in everything it says.
2) In a lot of theology, particularly popular Protestant theology, Jesus is the answer to a specific problem: We are fallen people, due to Adam’s sin. We inherit at least a fallen nature, if not actual guilt from Adam’s sin, and are thus unacceptable to God. We need salvation if we are to avoid hell. That’s what Christ is for. Without the Fall, Christ’s death seems pointless, since the problem it is designed to fix isn’t there.
Evolution probably destroys the Fall. Catholics have at times tried to say that even though we evolved, at some point a specific pair sinned, and all modern people are descendants of them. But this seems unlikely. There’s also the problem that it’s unlikely that our pre-human ancestors were sinless, which makes the whole Gen 3 narrative fall apart.
———————
I think once we accept scientific and historical evidence, there are serious challenges to a lot of Christian theology. I don’t think it challenges what Jesus was actually trying to do, but it certainly makes a lot of traditional theology hard.
I don’t see Jesus saying that everyone starts out as unacceptable to God. He saw lost sheep, who have to repent. But OT theology in general saw Jews as part of the covenant. When they sinned they needed to repent, but they didn’t start out damned. Later Jewish thought became more inclusive of non-Jews, and I think Jesus followed that approach.
The problem with this is once you don’t think people start out damned you have to ask what Jesus’ death was about. At that point you have to look at the atonement. Traditional Protestant theology takes one view of Jesus’ death, that he took the punishment that was due to us, and without it we would have to be punished ourselves with hell. But historically this wasn’t the only or even the earliest idea. Before Augustine’s time, Christians didn’t necessarily think everyone started off damned. Other ideas of Christ’s death ranged from it being an inspiration to it being a trick that caused Satan to overstep his bounds (by taking an innocent life) and lose his rights.
If you take seriously the idea that Christ was God made flesh, we might consider the idea that his death for us makes visible the character that God always had. He always loved us, and was always willing to go to extremes to help us, even if in loving us he suffered with us and on our behalf.
