Fact?
No, just the same level of evidence as anything else in the Bible. The difference between the Gnostic Gospels and the New Testament is what the Roman Emperor Constantine chose to keep and discard. Before the First Council of Nicaea, 325AD, there was all sorts of stuff in the bible that was edited out (under the guidance of God, allegedly ...) to make it more palatable for the Church as was. Mostly, they decided on whether Jesus was God or whether he was merely a perfect creation, but in debating this, they deliberately forgot to tell one whole sector of the Church that they'd decided to meet earlier than previously agreed. They met, closed the doors and left the Arians outside, unable to present their point of view. They also moved Easter[1] to a new date, as previously it was the Jewish Passover.
This council also introduced a whole pile of laws, designed to stop priests from having fun, essentially. Oh, and they excommunicated the people they locked out. Nice.
[1] Easter: Um, yeah, this one will make your head spin. Eostre is a pagan goddess that represented the Spring Equinox. The rabbits represent having lots of sex. Yes, it's an age old fertility ritual to celebrate the coming of spring. Not a lot to do with Jesus, but they tagged his resurrection on a f*ckfest in an effort to clean things up.