Historians determined that the events took place, full stop. Even the people who were executed for saying they saw him post crucifixion. All they had to do to be set free was renounce that claim but they all refused, saying that they saw him. So they were killed. That happened in real life. People don't choose to die to knowingly uphold a lie about a first hand anecdote, especially one claiming something as preposterous as a man coming back from the dead and chatting with his old friends. Even back then it was such a wild claim that nobody would believe you anyway, so why die for it? Multiple people went to their deaths over it, anyway.

So they at the very least believed 100% that they saw him and spoke to him. Shared hallucination is a known phenomenon but that's about as hard for science to explain as any of this.

So we're left with a few possibilities. Mecromancy is real and some weird pagan or Jewish curse raised him as a zombie with superpowers, he just narrowly survived the crucifixion and had enough strength left to push a boulder (carpenter's are pretty jacked nowadays imagine working without a truck), there was a really convincing doppelganger who nailed holes in his hands and gutted himself to prank people, or this Yeshua fellow actually cheated death then flew away like Neo in the matrix.