The Gospel According to Bart.

Dan Wallace deconstructs Bart Erhman's biased textual analysis.

This psychological analysis seems accuate:

Second, what I tell my students every year is that it is imperative that they pursue truth rather than protect their presuppositions. And they need to have a doctrinal taxonomy that distinguishes core beliefs from peripheral beliefs. When they place more peripheral doctrines such as inerrancy and verbal inspiration at the core, then when belief in these doctrines starts to erode, it creates a domino effect: One falls down, they all fall down. For a clarification of what I mean by "core beliefs" and "more peripheral doctrines" see "My Take on Inerrancy." It strikes me that something like this may be what happened to Bart Ehrman. His testimony in Misquoting Jesus discussed inerrancy as the prime mover in his studies. But when a glib comment from one of his conservative professors at Princeton was scribbled on a term paper, to the effect that perhaps the Bible is not inerrant, Ehrman’s faith began to crumble. One domino crashed into another until eventually he became ‘a fairly happy agnostic.’ I may be wrong about Ehrman’s own spiritual journey, but I have known too many students who have gone in that direction. The irony is that those who frontload their critical investigation of the text of the Bible with bibliological presuppositions often speak of a ‘slippery slope’ on which all theological convictions are tied to inerrancy. Their view is that if inerrancy goes, everything else begins to erode. I would say rather that if inerrancy is elevated to the status of a prime doctrine, that’s when one gets on a slippery slope. But if a student views doctrines as concentric circles, with the cardinal doctrines occupying the center, then if the more peripheral doctrines are challenged, this does not have a significant impact on the core. In other words, the evangelical community will continue to produce liberal scholars until we learn to nuance our faith commitments a bit more, until we learn to see Christ as the center of our lives and scripture as that which points to him. If our starting point is embracing propositional truths about the nature of scripture rather than personally embracing Jesus Christ as our Lord and King, we’ll be on that slippery slope, and we’ll take a lot of folks down with us.

That kind of thing happens all the time.  With respect to Bart Ehrman it is clear that he still views the early Christian world in the same way that he viewed it when he was a fundamentalist. For example, when Ehrman discusses the dissemination of the Gospel he sees the early Church acting as if it was 1979: conversions occur through enthusiasm and a telegraph game of the Gospel, rather than by a potential member being introduced into a Christian community with professional teachers who take the time to memorize the teachings of their faith.
Via Tu Quoque.