This is not really true; collective or group hallucinations are well-documented, and can be quite lifelike. But hallucinations need not be group occurrences for stories to arise about a shared group experience, and the memory of experiences can be socially molded as well. There is a rather good discussion of these matters in the book American Apocypha with regard to the testimony of the witnesses of the "golden plates" possessed by Joseph Smith; what is reported as a literal visual experience shared by a group belies a much more complex situation with elements of group hallucination and after-the-fact revising of memories (e.g. what originally was separate experiences of physically holding the plates under a cloth and later seeing them in a vision became conflated as literally seeing and holding the plates at the same time), particularly in the case of those who did not have the "correct" experience at the time (such as one fellow who failed to "see" the plates the first time he tried).
I do not believe that the "testimonies" of the 11 LDS "witnesses" can be held in the same esteem as testimonies of the disciples of Jesus. First, while all of the disciples were willing to suffer and die for their beliefs, 6 of the 11 LDS "witnesses" left the Mormon Church. Further, even if the LDS "witnesses" actually saw the golden plates, this tells us nothing of what was written on them. After all Joseph Smith had to wear magic glasses in order to interpret the alleged writings on the golden plates. There is no archeological evidence that even remotely confims any of the stories in the Book of Mormon. On the other hand, there is evidence outside the New Testament that confirms the testimony of Jesus' disciples (e.g., the empty tomb, and the conversions of Paul and James). Lastly, there are huge archeological issues with the Book of Abraham, while no viable evidence against Christianity exists.
I think the position is generally that the empty tomb is a later narrative development in the resurrection tradition
That's nice to know. However, Dr. Gary Habermas has done research that demonstrates that 75% of the scholars he polled (from conservative to liberal) believe that the tomb was empty based on the narratives. Habermas even quotes Bart Ehrmann as saying:
Historians, of course, have no difficulty whatsoever speaking about the belief in Jesus’ resurrection, since this is a matter of public record. For it is a historical fact that some of Jesus’ followers came to believe that he had been raised from the dead soon after his execution.
Further, William Lane Craig places the Christian formula found in 1 Corinthians 15:3-5 to within five years of the resurrection event. Not to mention Peter's first sermon as recorded in Acts 2.
There is ample evidence to hold to historicity of the resurrection. Opposing theories do not hold their own when analyzed objectively. SO there must be another reason for unbelief.
