I originally like Bart Ehrman's work. I thought that his courses on the Teaching Company were very good. However, as I've listened to Ehrman's popular stuff, such as his debates and interviews, I've come to wonder how much I can trust Ehrman. Simply put, Ehrman says stuff that he knows is either overstated or wrong.
It's not just me who says this. William Lane Craig points out that there is a "Good Bart" and a "Bad Bart." "Bad Bart" will make the claim in popular circles that there are more errors in the Bible than there are words, and will foster the impression that we really can't know for sure what the original text said. However, when called out on it, "Good Bart" will forthrightly admit that we actually do know what the original text said and that the "errors" can be corrected or aren't all that significant.
Similarly, in one debate, in support of his argument that the post-Resurrection appearances of Jesus were delusions, Ehrman argued that grieving people have such delusions all the time. When it was pointed out that people don't often have the same delusion, Ehrman said, "yes, they do", leaving the impression that he had some academic support for the claim that groups of grieving people have been known to have the same delusion.
It turned out that Ehrman was conflating different events. Individually, grieving people have been known to have visual and tactile experiences of their dead loved ones, but not in groups. Ehrman's reference to "group delusions" was to things like the vision of Our Lady of Fatima, which have never been shown to be delusions. They might be delusions and atheists might assume they are delusions, but most people would never confuse an individual grieving person with the mass phenomenon of Fatima. By carefully omitting the important details, Ehrman was using his role as "neutral academic" to mislead listeners.
Darrell Bock issues a similar warning with respect to Erhman's academic writing. Bock discusses Erhman's The New Testament: An Historical Introduction:
This volume is one of the most popular texts for early Christianity classes in the USA, which is why we are discussing it in the class. It is clearly written and engaging. It summarizes many commonly held positions that are held about the Bible and New Testament in some scholarly circles. It is important to know what generations of college students are being taught in the name of knowledge and understanding. I am discovering that it is what Ehrman does not mention that is often important.That really does sound like the "Bad Bart" of the debates and popular lecture.
For example, in treating the authorship of the gospels (all of them), he does not address any of the external evidence for authorship that comes from sources like Eusebius or Irenaeus or any of the canonical church lists. This is historical evidence and ignoring it prejudices his volume's work, cutting out one of the two key factors one has to address in treating authorship, namely external evidence for a work's authorship. Vincent Taylor and C. E. B. Cranfield regarded such evidence as decisive in treating this question in terms of Mark's gospel.
I am quite aware that many think the internal evidence is against such an authorship claim for Mark (and Ehrman does present those arguments). Those arguments can be addressed. So given a fair debate over the issues that lead one to think about who wrote a gospel, here is a point the claim Mark did not write the gospel has to deal with. What commends Mark as the author, if we are going to simply pick someone to enhance the reputation of a gospel when no one supposedly who knows the author is (which is what the alternative view claims is the situation)? What is Mark's reputation? He failed to survive the first missionary journey and caused a split between Paul and Barnabas according to Acts. So how does randomly attaching his name to the book enhance that gospel's credibility? Such a theory does not work here. Mark's reputation, such as it was, on its own does not enhance the credibility of the work. More than that, the tradition also consistently associated Peter with Mark, so why was this gospel not simply called the Gospel of Peter, if one is free to name any author the church could choose? Given a choice between Peter and Mark on the basis of reputation, Peter would be the obvious choice. Something else must be at work, namely, a tradition careful about who it called an author, naming someone who in this case had an otherwise less than stellar resume. Arguments like the ones I just noted go completely ignored in his volume (and these are fair historical questions). So user beware that if you are being asked to use this text in a college class, some key points are not even being raised.