1. Genesis says that God created everything, and that "it was very good". Theistic evolution would require that no such thing happened. Or it would require that the millenia of death and destruction wrought upon humans prior to the mythical events of Genesis 1 was "very good".
2. While the Bible is not science, it presents things as fact that touch on history, biology, and other factual areas. The suggestion is that the authors of the Bible simply weren't privy to this information and were, well, wrong. This brings God into question. Why couldn't He tell them what was right?
3. Paul refers to Adam as a real person, the "first Man". Jesus is "the second Man". However, if Adam was not a real person, what was he? If no actual sin occurred (the reason Paul references Adam as the "first Man" as the source of sin entering the world), what did occur? If there was no such event, what event is the Bible referring to? What is the source of the curse on the ground of Genesis 3 and the curse of creation in Romans 8? If there is no "first Man", in what sense is Christ "second" anything?
4. If theistic evolution is true, it calls into serious question the capabilities of the God I worship. It would require that He was incapable of properly informing the writers of Scripture about the truth. Further, He played on His own inability by commanding His people to "honor the Sabbath" in the same way that He rested on the seventh day ... which, of course, never happaned. "Do what I never did," He commands His own. It would demand that the God, the Holy Spirit, failed to get across the fact that Genesis was just myth to 2000 years of Christendom. It would suggest that God is using Science as a crutch to finally explain to His followers what He could never get across in the history of Man.
5. The Bible is riddled with myths and legends. You won't really know where they are. You'll just likely have to wait until Science points them out to you. It's good to have an atheistic materialism around to correct the errors of millenia of Christendom so we can finally get this stuff straightened out. Did God create the heavens and the earth? No. He "made" them by natural processes like a farmer "makes" a crop of corn. Did God form Adam out of the dust? Don't be ridiculous! There was no actual Adam. Was there a worldwide flood? Of course not! Science can inform you of better than that. Localized, maybe. Did Jesus rise from the dead? Of course He did!! Oh, wait, I suppose Science would disagree. Maybe not. Maybe it's another legend. You know, telling us about victory and joy and that kind of thing. No, certainly not real.
6. Evolution starts with the simple and works its way up. Creation operates as creation built for a purpose -- humans. In Evolution, Man is an after-thought, the latest in an ongoing changing universe. In Christianity, we were the point -- the created beings who would reflect His glory. Theistic evolution would like to make us an after-thought that was the point.
7. Since Genesis is full of myths and the Old Testament is riddled with "historical events" that didn't really occur, what am I to believe? When Paul bases his statement about women in leadership on the order of creation and no such order of creation occurred, what am I to believe? When Paul says that Eve was deceived when no Eve existed, what am I to believe? When Paul compares and contrasts Christ to Adam and no Adam ever existed, what am I to believe?
8. Where else? Where else do we give in? We're surrendering the historical comprehension of Genesis. Science has informed us we were mistaken. Science also assures us that no Flood ever occurred, no silly crossing of some "Red Sea" could have happened, no extended day happened in Joshua's time, Hezekiah never had the shadow move, and certainly Elijah didn't raise the widow's son. Or Jesus Lazarus. Nor, in fact, is it possible that someone named Jesus rose from the dead. It's all pretty clear with modern Scientific examination that none of this could happen, so let's put aside the myths and legends of a 2,000-year-old book and move on with fact, okay? Where else do we surrender? How about God? Is He now just "the God of the gaps", the filler for the empty spaces while we wait for Science to figure out the rest?
That last, in fact, is the bottom line. We're holding two truth claimants. One is the Bible. One is Science. Often they agree. (Happy day!) Sometimes they don't. So, what do we do when they don't? The current trend is to figure out what we did wrong when we read our Bibles and, if possible, set aside what has always been the case in order to subscribe to a truth claimant centered on a naturalistic world with open hostility to anything spiritual. Yeah, that sounds like the best approach. Let's do that.