Pilate, a man who knew his crucifixions if anyone did, was surprised to hear he was dead. It normally takes days to die on the cross. The other two were still alive. When he was stabbed with the spear, blood and water gushed out, dead bodies don't bleed (I'm aware of one explanation for that, but the spear would have to have been so precisely placed that I think it is most unlikely). Somebody unrolled the embalming cloths in the tomb - not required if he had ascended to heaven.
That's the biblical evidence. Then you have the lies and myths built up around interpretations of poor bible translations, like the guard being a crack Roman guard so the tomb couldn't have been opened from outside (lie) or Jesus being unable to walk after the crucifixion because of his nail pierced feet (myth).
