Why can't Christians Verify Exactly Where Jesus Was Buried?

[Aractus]

Not at all. A relatively recent example is Patton's Speech, which he gave several times, with varying verbiage in each instance. A historian took the time to interview soldiers who'd heard it, and using their recollections, reconstructed the speech, in gist if not exact wording. If Matthew had that letter available (and I don't know that he did, nor it relevant to my overarching point that such methodology is not "illogical") --if Matthew had notes covering the key points, he could be able to reformulate the speech, especially if he only had one version to contend with -- such a state of affairs would simplify his task.

You cannot reformulate the Sermon on the Mount from James, it is substantially different and includes other areas of Jesus's teachings that are consistent with but not included in that sermon. What's most important of all is that almost nothing in James is found in the gospel of Mark at all. It is exclusively from a separate account of Jesus's teachings (that is we have Mark as one source, and another source whether Q or James himself or an oral tradition for James). In addition to the Sermon on the Mount we have yet another sermon (Sermon on the Plain) which is substantially similar, but not the same, to it found in Luke. Now they could be the same sermon that has been recorded in two different ways, or they could be Jesus delivering the same or similar sermons on different occasions (which is the more likely because we would expect a preacher to give different audiences the same messages at different times).

Is it not possible for a writer to use more than one source? Indeed, if I were reporting on the man whom I thought to be the son of my god, I'd certainly go to longer lengths than using one source.

Again, using James as a source would not give the sermon on the mount because nowhere does James inform the audience that he is directly quoting Jesus.

Joseph of Arimathea's tomb is largely irrelevant, because it's a small tomb about the size of a small fireplace that is designed to be use intermittently and not as a final resting place (it's a bit like what a morgue is today, where the body is placed in a shroud and later transferred to an ossuary).

If[/if] Jesus existed, and [i]if he were placed there, might this not possibly explain the Biblical story with appeal to resurrection?[/i]

I have made the point that it completely explains the resurrection belief. In fact the resurrection belief itself couldn't have happened without a crucifixion, it was formulated sometime after the death of Jesus when the disciples/followers/believers/Christians were trying to reconcile their beliefs with a dead messiah who made prophecies. "Mark", Peter, and James are not aware of (or at least there's no evidence that they're aware of) a resurrection belief, however "Mark" and Peter both have the belief that Jesus ascended after his death. That is that he (or rather his spirit form) ascended to the heavenly realm. The resurrection takes places after this, and has Jesus coming back to meet his disciples and followers for 40 days before again ascending to the heavenly realm. This belief is first recorded by "Matthew" and Luke - after the writings of James, Paul, and "Mark". Paul believes very strongly that Jesus is alive and well up in the celestial realm, it's central to his belief system, but aside from an obscure early creed in Corinthians 15, he never makes direct reference to appearances of Jesus - let alone to a resurrection where he spent 40 days confirming his heavily authority to his followers after his death; and if Paul was aware of that it's something he surely would have mentioned, because that's what gives authority to Jesus 20 years after his death when he is writing and claiming that his authority comes from Jesus and God.

Similarly the story that Paul met the resurrected Jesus on the Road to Damascus is an expansion by Luke (or rather whoever told Luke the story) and this is obvious because Paul himself says he "had a revelation about Jesus" on the Road to Damascus in his earliest known epistle (Galatians), he doesn't even say that he had a vision of Jesus. There are several obvious reasons to prefer Paul's account over Acts 9 in any case: 1. Paul's delivers a first-hand account of own experience, whereas anything Luke has to say in Acts 9 is hearsay by comparison; 2. Luke's versions invokes the supernatural whereas Paul's does not; 3. This did not take place within the 40 days of Jesus's resurrection appearances, therefore he wasn't on Earth to appear to Paul anyway; 4. Paul's version is simple and direct, Luke's is convoluted and complicated which is indicative of an expanding mythology surrounding Paul's experience. On that last point: that's what we would expect if Paul has told this story to people in the way he writes about in Galatians 1 - it does indeed leave much to the imagination, and it wouldn't take much for other Christians - including those like Luke who knew Paul personally - to become convinced that what Paul meant when he told this story is that he saw Jesus appear to him. And of course there's 5. which is that Acts 1-12 is written in the historical narrative, and Acts 13-28 is written in the first-person narrative which strongly suggests to scholars that Luke relied hevily on his own first-hand knowledge for the latter half of the book, but that for Acts 1-12 (in which Paul's conversion happens in Acts 9) Luke relied on 3rd-hand information (stuff that he was told by others). He was a physician, not a historian, therefore his credentials for discerning historical validity are not great either - when you compare to someone like Josephus who was a historian, not a physician.