Did Homer, Plato and Aristotle exist, or were they mythological characters?
However, the words of Jesus were quoted many times in the first and second century by followers like: Luke, Mark, Clement of Rome, Mathetes, Polycarp, Ignatius, Barnabas, Papias, Justin Martyr, Iranaeus, etc.
Polycarp even claimed to be an original disciple because as a child he sat at the feet of John. He also learned fromt the other disciples.
Polycarp was stong in his beliefs and refusing to flee, suffered martyrdom after a dream he would die by fire. His congregation gathered up his burnt bones and cherished those charred remains of their beloved bishop as if they were the most precious jewels.
THE EVIDENCE IS THERE IF YOU HUNT FOR IT AS RARE GOLD.