What one thing would disprove Christianity to you?

[Kirbmarc]

With that said, my answer is this. If you could prove to me that Jesus was not crucified, or if you could provide sufficient evidence to prove that his body is not risen, then that would prove I am wrong

Since a resurrection is an extraordinary claim (it goes against the laws of physics) and we don't have evidence for it expect from the hearsay from the gospels (which doesn't count that much), then rationally speaking you shouldn't believe in Christianity, since there is no prove that his body has risen.