Well, Easter has come and gone again. That seems to be a good time to talk about the resurrection. Because many Christians have been talking about it. How else can we explain the empty tomb if Jesus wasn't magically resurrected via the power of an ancient bloodgod? It's the only explanation that makes sense! (rolls eyes)
The problem with the question is its loaded nature. The empty tomb is presented as a fact. This has some major credibility problems.
Problem 1: Timing
The empty tomb isn't used as proof of Jesus' divinity and resurrection until we get to the gospels. The (genuine) letters we have from Paul do not mention it. Nor is it present in other early NT letters. For something that's supposed to convince us all that Jesus was divine and resurrected, its absence for decades in early Christianity literature is astonishing.
The gospels are generally reckoned to be written after Jerusalem was besieged by the Romans (70 CE) because they're not referenced in earlier Christian documents. Paul seems completely unaware of them. And prophecies of Jerusalem being sacked are always easier to make after the event...
The sequence for the gospels is usually reckoned as Mark, followed by Luke and Matthew, and finally John. This spans around 30-40 years. And all are long after the alleged event. The gap between when the empty tomb alleged occurred and when it's first mentioned is extraordinarily large.
Edit: this alone persuades me that the empty tomb was a later contrivance.
Problem 2: Inconsistencies
Despite the synoptic gospels (Mark, Matthew, Luke) patently using the same sources, they can't keep the empty tomb story straight. Throw in John and it gets worse. The number of women who went to the tomb, when they went, what they saw at the tomb, what they did afterward, whether they were believed or not are all inconsistent across the gospels.
The Apologist gambit is to assert that this is what we expect with eye-witness accounts. No. It's consistent with a bunch of people who didn't balk at making things up to sell their religion.
Edit: the women are not the only inconsistency of course. E.g. Matthew has guards and a seal that everyone else seems to forget. The accounts are more what we'd expect with oral traditions and attempts to establish the orthodoxy or early doctrines over several decades.
Problem 3: It conflicts with Roman practice
As far as we can tell Romans did not normally allow crucified victims to get buried in tombs. Crassus left thousands of ex-slaves rotting on crosses after the suppression of the Slave revolt. Normally crucified victims were left aloft to be picked clean by birds and the like.
To be buried, and buried ceremoniously instead of in a common pit, is a deviation that begs for explanation.
Edit: this is the weakest objection I have, and one that Richard Carrier has explained to my satisfaction. It is highly likely Romans allowed the locals to maintain their traditional burial practices.
Problem 4: Joseph of Arimathea
It has always struck me how much of a Deus ex Machina Joseph plays. In order to get Jesus from the cross, into a tomb and in the time available, requires a very powerful and capable character. There's nobody in the disciples capable of pulling this off.
Enter Joseph. He fixes all the problems with the plot. First, he's politically powerful. He's part of the council that condemned Jesus. But like all superhero fiction, he has a secret identity. He's also a disciple of Jesus. He's influential enough to persuade Pilate to take the body off the cross. He's also rich. This is also necessary for the plot. They have to buy linen cloth and 100 pounds of myrrh and aloe that evening. He's also already got a tomb ready. Every plot-hole (bar one) is immediately fixed. Evening might be approaching when he asked Pilate for the body, but Jesus is lying in a shroud, in a tomb, with a stone covering the entrance in time for his resurrection. Phew!
The remaining plot hole of course, is there isn't enough time to get this all done in the time available.
Joseph's appearance in the story is dramatic. He's not mentioned in the gospels before this. And he disappears just as dramatically. He's never mentioned again. He's not mentioned in Acts, he's not mentioned in any of the letters preceding the gospels. Paul, Peter and James have no recollection of him at all. He's a powerful and connected guy with massive influence, and nobody mentions him?! Amazing.
Joseph only has one job. He appears at exactly the right time to fill in a bunch of critical plot-holes, and then disappears. He has the traits of a literary invention that appears decades later when the empty tomb story gets added to the Jesus legend- not the traits of an historic person.
Edit: Even the locale of Arimathea appears made up.
(If you want a much deeper analysis of Joseph of Arimathea, I recommend John Loftus' blog).
I don't feel that I need to explain the empty tomb, because I don't think there was one. Early Christendom was plagued with doctrinal problems. Hints of this are preserved in the letters of Paul, James and others. This also created a range of heretical sects, such as the Arians.
The gospels weren't written to be histories. They were written to convince people that Jesus was the Messiah and of divine origin. And by drawing on the authority of Jesus and the early disciples, they could be used to resolve doctrinal disputes. Was the resurrection a mostly spiritual personal visionary event? Or was it a physical event? For anyone who believed in a physical resurrection, the canonical Gospels make a perfect argument. And they get more elaborate the later the gospel is composed. It's the last gospel, John, that introduces Thomas as the clincher for the physical resurrection.
So either major scientific laws were broken to miraculously bring the offspring of an ancient god and virgin back to life. Or the belief that the resurrection was a physical event evolved slowly in a community that was willing to add embellishments that showed this, in retelling, over decades. It's not really difficult deciding what's the least plausible.