Rather than cite more sources, I will point you to the collective amount of material that was written about Jesus by his early followers and even opponents such as Paul who spent time as one of the Church's greatest opponent and then became one of its greatest missionaries. These were not men who stood to gain anything by the telling of these stories, but who did so at risk of death. In fact, not counting Judas who committed suicide, all but John were martyred for preaching that Jesus Christ was the only begotten Son of God and who came to reconcile us to God by his sacrifice.

These are the same apostles, mind you, that were missing in action when Jesus was facing Pontius Pilate except for Peter who denied he even knew him. Why the change of heart? Why the Resurrection, of course, and the subsequent giving of the Holy Spirit! What else would convince not just one or two or even five or six but all of the disciples to go out and start telling the story. You have to hypothesize some mass conspiracy among dozens of authors, many of whom wrote under fear of death, and who had nothing to gain from the telling. How do you explain that? You are left trying to explain that these men all died for writing about someone who never actually existed. (Let's not forget the Koran which mentions Jesus as well and even acknowledges he had the power the raise the dead).