There is an actual non-papal source that proves Jesus existed. What is controversial is that he performed miracles, or that he was the Messiah. So in other words, his actions could have been fiction, but he himself, was historical. The only source that says Jesus had a certain "power" is the Bible, and the Bible's stories were an oral tradition for a hundred years or so, so it isn't a really reliable source. But who knows?
There, as of now, has been no proof to prove that Jesus really does exist - but there is plenty of proof to show that his life was based off different people. Political commentator Bill Maher confronted a Christian man about this, and this is part of what he said.
Maher: Written in 1280 B.C., the Book of the Dead describes a God, Horus. Horus is the son of the god Osiris, born to a virgin mother. He was baptized in a river by Anup the Baptizer who was later beheaded. Like Jesus, Horus was tempted while alone in the desert, healed the sick, the blind, cast out demons, and walked on water. He raised Asar from the dead. “Asar” translates to “Lazarus.” Oh, yeah, he also had twelve disciples. Yes, Horus was crucified first, and after three days, two women announced Horus, the savior of humanity, had been resurrected.
Hmm, the similarities are uncanny, right?