This is the second fact that supposedly is agreed upon by the majority of scholarship regarding the life of Jesus and his followers. Before delving into the evidence used to support this claim, I want to consider first a key assumption in this claim that in my mind somewhat undermines its usefulness to the Christian apologist.
I don't think the evidence supports the claim that the disciples believed Jesus rose from the dead and appeared to them. But let's assume that the majority of scholarship is right, and that they did. Does this mean that the disciples thought Jesus appeared to them in a physical sense? It doesn't. In fact, according to Greg Koukl, who admitted this to me in a phone conversation July 8th, (11-13-07 edit. As per Melinda's comments, it appears that Greg and I misunderstood each other and in fact he did not make the admission I claimed he made) scholars do no think the disciples believed that Jesus appeared to them physically.
This is a very important element of the apologists' argument. People even today claim that Jesus appeared to them. They don't always think it is a physical encounter. Yet some of them would be willing to give their lives for the messages they think they received from Jesus, who appeared to them. I know such people personally.
Paul doesn't actually say that he encountered Jesus in a physical way, nor does he say that the disciples experienced Jesus in this way. Habermas and Licona of course want to believe that Paul taught that when we rise from the dead we rise physically. I disagree that this is what he taught, and I'll be dealing with their arguments that it is in a later post. But even if it were true that he thought that, this would not mean that he claimed to have seen a physical Jesus. He would have to think that Jesus could appear to him in a vision even if in fact Jesus was raised physically.
Licona and Habermas number the supposed undisputed facts as "4+1". That is, the first four facts are supported by the vast majority of scholarship. The fifth fact (the empty tomb) is supported by a majority or scholars, but not as strong a majority as the previous 4 facts. They claim that 75% of scholarship accepts the empty tomb, while the other facts are supported by a larger majority.
If in fact the disciples believed Jesus rose from the dead in a non physical way, then really it becomes pretty easy to make sense of the first 4 facts in a non-supernatural way. And as Habermas and Licona themselves admit (p82) natural explanations should be considered before supernatural ones. Jesus was crucified, some of the disciples and some others (Paul and James) thought he had in some sense appeared to them. Why they thought this we can't exactly be sure, because they don't give us a lot of details. Paul and James became followers. It's really not too hard to imagine that this could actually happen.
If a person were to accept that Jesus was buried in a tomb, then a natural explanation would need to account for that, and the naturalist might posit theories that seem unlikely. Perhaps the body was stolen by somebody other than the disciples, or by other committed followers that we don't know much about. Perhaps followers went to the wrong tomb. Perhaps Jesus survived and slipped away from the public eye. These theories seem pretty unlikely (and are dealt with by Licona and Habermas on pages 95-103 in a very weak fashion in my opinion). But you know what else seems unlikely? It is unlikely that a person that was dead for three days was supernaturally raised from the dead. We have zero confirmed cases of that event, as opposed to a handful of cases of the unlikely scenarios that I mentioned. Weighing one unlikelihood against another, a person must decide which they think is more unlikely.