There's a number of books, several by secular authors, who agree the gospels accepted as canon do not read as embellished works. No beginning to a religion would have women as witnesses, the disciples looking as stupid as they did, nor allow incidents like Gethsemane, the cross etc to be present in them.
Also, why would the 12 have let themselves be killed in such horrendous ways to defend an embellished truth?
Not to mention, the gospels contain frequent claims that Jesus made suggesting He was God (John 8 / 10), or self claims (I am the son of man, or the Christ, or the son of God, etc).
You may disagree with them, which is your right, but He was very clear.
The gnostic gospels were a melding of Hellenistic philosophy with Jewish mythology. The do not sit consistently with the OT nor what the Messiah was to come to achieve. They're interesting reads, but sit well outside the arc of the OT and therefore were summarily dismissed. Not to mention, they weren't written by eye witnesses either.