It certainly didn't prove the existence of an afterlife. Unless your burden for "proof" is very low.
They had no cameras, vcrs tape recorders, and only very low resoultion art forms at the time. The ONLY evidence was WORDS, left behind on not very archievable substances.
We have some TESTIMONY from MANY witnesses that this JESUS fellow ROSE FROM THE DEAD! Now, these words are either true, false or madness - I see no other choice.