An empty tomb doesn't prove the resurrection, granted, but remember that this is just one of the five minimal facts. And it's entirely congruent with the beliefs of the disciples, Paul, and James that Jesus rose from the dead, since a resurrection implies an empty tomb. Shortly after Jesus died from crucifixion, his disciples believed that they saw him risen from the dead. They said he appeared not only to individuals but in several group settings-and the disciples were so convinced and transformed by the experience that they were willing to suffer and even die for their conviction that they had encountered him.
Then we have two skeptics who regarded Jesus as a false prophet-Paul, the persecutor of the church, and James, who was Jesus' half brother. They completely changed their opinions 180 degrees after encountering the risen Jesus. Like the disciples, they were willing to endure hardship, persecution, and even death rather than disavow their testimony that Jesus' resurrection occurred.
Thus we have compelling testimony about the resurrection from friends of Jesus, an enemy of Christianity, and a skeptic. Finally, we have strong historical evidence that Jesus' tomb was empty. In fact, even enemies of Christianity admitted it was vacant. Where did the body go? If you asked the disciples, they'd tell you they personally saw Jesus after he returned to life.
So we've looked at relevant sources, and we've applied responsible historical methodology. Now we need restrained results. We have to ask ourselves: What's the best explanation for the evidence-the explanation that doesn't leave out any of the facts or strains to make anything fit? My conclusion, based on the evidence, is that Jesus did return from the dead.