"How do you explain Jesus' appearances to the apostles?" is a standard gambit of Christian apologists.
Their next move is "Since all naturalistic explanations are inadequate, the only logical explanation is that Jesus actually rose from the dead."
Lately, I have been inclined to simply decline the gambit. As I explained in a recent post, given the available sources, I don't expect to be able to explain their experiences. All I have are fantastic stories written decades after the fact by true believers. If all my information about 1947 Roswell, New Mexico came from the books written by UFO nuts decades after the fact, I would have little chance of figuring out what really happened. What possible chance do I have of figuring out what really happened to the followers of a 1st century Galilean peasant using anonymous religious propaganda based on unknown sources which are removed an unknown number of times from the eyewitnesses in an oral tradition spanning decades?
However, for anyone who cares to accept the apologists' gambit, Kris Komarnitsky's book, Doubting the Resurrection: What Happened Inside the Black Box? is an excellent resource. Using mainstream scholarship in the fields of psychology, sociology, and New Testament studies, he offers an entirely plausible and thoroughly researched naturalistic hypothesis for the resurrection accounts found in the New Testament. All you need is a cup or two of grief-induced hallucination and a couple of tablespoons of cognitive dissonance reduction combined with a dusting of common human foibles like ignorance, exaggeration, superstition, prevarication, gullibility, and wishful thinking. Komarnitsky doesn't claim that we can establish his theory as historical fact, but he shows that natural processes are more than sufficient to explain the data.
The first six chapters of the book are terrific. Komarnitsky offers a plausible explanation for the origin of the stories of the empty tomb and the honorable burial by Joseph of Arimathea. (I particularly appreciated his distillation of what scholars know about what kind of burial might have been likely for a crucifixion victim in 1st century Palestine.) He gives excellent examples of cognitive dissonance reduction in religious movements that coped with failed expectations by reinterpreting and reinventing their beliefs. The detail may be a little overwhelming for anyone who is new to these topics, but the thoroughness will be appreciated by anyone who frequents the dark corners of the internet where these issues are debated.
I was less impressed with seventh chapter which compares his hypothesis with the "minimal facts" defense of the resurrection offered by Michael Licona and William Lane Craig. It is the only completely new chapter in the 2nd edition of the book, and while it contains some useful information, I found it somewhat muddled. I think the problem is that the "minimal facts" approach is apologetic smoke and mirrors and Komranitsky tries to engage it as if it were legitimate historiography. The first six chapters of the book refute the apologists' gambit using well-established scholarship, but in the seventh chapter, he chooses to play a game in which the apologists are allowed to make up their own rules as they go along.
In the eighth chapter, Komarnitsky engages with another standard apologists' gambit, "How do you explain the rapid spread of Christianity if Jesus didn't really rise from the dead?" His explanation is lies in the transformative power of the concept of equality before God. While I think it is a reasonable hypothesis and I would like to believe it, I'm not sure whether it is really true, and I don't think the case for it can be made in a single chapter.
Some skeptics may be disappointed that Komarnitsky isn't as hard as he might be on the apologists and their double talk. I know I was a few times. However, he is not out to bash religion in general or Christianity in particular. He just wants to show that the origin of Christianity can be explained naturally and I think that he does so very well.
As time allows, I hope to discuss the book in more detail.