If Jesus had tried walking around in a Roman province in an actual dead human body for 40 days, Romans would have seen him and crucified him a second time and done whatever it would have taken to ensure that he STAYED crucified. I assume the resurrection was the sort of thing Julian Jaynes described but it was not any sort of a mass hallucination and to the people who experienced it, it was utterly indistinguishable from Jesus having come back in his own corporeal (and dead) body. That IS the way Jaynes described that sort of experience and that is also the way that the OT ghost story involving Saul, the prophet Samuel, and the "witch" of Endor reads.
What?