Theistic evolution seems to be on the rise. With the publication of Collins' The Language of God along with Coming to Peace with Science and Dinesh D'Souza's What's So Great about Christianity, theistic evolution is getting more of a foothold in evangelical churches. My personal opinion is that the reason this is happening is because an increasing number of Christians are recognizing the folly of young-earth creationism. Old-earth creationism continues to be a minimally publicized position. So people just kind of jump from young-earth creationism to theistic evolution because they are unaware of any other alternative.
Meanwhile, Reasons To Believe continues to take a strong stance against theistic evolution and affirm special, miraculous creation (as do I).
This has gotten me to thinking about one of the theological problems that I see with this view. (I'm not qualified to speak to the scientific problems with theistic evolution. I'd refer you to RTB's numerous resources on the subject.) Many (not all) theistic evolutionists view Genesis 1-3 as myth, meaning non-historical. Although I would concur that Genesis 1-3 shares some literary characteristics and themes with other ancient near eastern myths, that doesn't automatically mean that it actually IS a myth.
Related to this, there is a growing trend to dispose of a historical Adam and Eve. This has gotten me to thinking about whether or not this is actually an essential doctrine. After some thought and study, I'm becoming increasingly persuaded that a belief in a historical Adam and Eve is, in fact, a critical Christian doctrine. Here are three reasons why:
1. Adam stands at the root of Jesus' family tree according to Luke 3:38. Wouldn't it seem a little odd if everyone in Jesus' genealogy is a true historical person, only to arrive at the root of the whole thing and pronounce Adam a mythological being? That just doesn't seem to fit.
2. Paul makes a tight analogy between the way sin entered the world (through one man, Adam) and the way righteousness and justification is gained through the "second Adam" (Romans 5:12, 15-19 and 1 Corinthians 15:22). An analogy has its greatest strength when the two things being compared are actually alike. How could Jesus be compared to a mythological being when Jesus Himself is a real human being, especially given the context of 1 Corinthians 15 where Paul's entire argument for the resurrection rests on the fact that Jesus was a real historical person and that his resurrection was an actual historical event? Saying that Adam is anything less than historical would seem to make Paul's argument fall down like a house of cards.
3. 2 Peter 3 recounts both creation and the flood as being historical events which in turn provide a sure foundation for believing in future judgment and eternal life. If these events as recounted in the early chapters of Genesis are merely myth, then the rationale for believing in a future in heaven collapses as well.
Based on these points, I would argue that a belief in a historical Adam has a direct connection to the Gospel itself, as well as the historicity of the Bible in general.
Those are my thoughts at the moment. I'm still sort of processing all this.