Are Gnostic Gospels Authentic?

A question I was asked back in August:

Q: What is the authenticity of Gnostic Gospels? Couldn't they have been written for selfish interests?

 A: Several Gnostic works claim to record the words or acts of people mentioned in the New Testament such as the apostles Thomas and Phillip, or Mary Magdalene and Judas. If by “authentic” you mean were they written by these people, then the answer is no, they are not authentic. Most scholars believe these books were written in the 2nd and 3rd centuries or later, although the so-called Gospel of Thomas was probably written around AD 100 - 110 and has portions that seem to be traditions from the earliest days of the church.

Could they have been written for selfish interests? Of course, but they also may have been written to publicize their teachings and provide teaching materials for their followers. When these books were written Jesus was just getting famous as the latest ‘mystic master’ in the Roman Empire. Gnosticism had been a tendency of long standing in the Mediterranean world deriving from the platonic teaching that matter is evil and the liberation of one’s soul from matter was the aim in life — and afterlife.

"Christian" Gnostics appeared at the end of the 1st century attempting to link the cache of Jesus’ name with this very popular Platonic philosophic idea. After all, the actual Christian teaching of Jesus and hi apostles with its bloody crucifixion, its ridiculous idea (to Greeks and Romans) of a man returning bodily from death, and its rigorous insistence that no other gods be worshiped — including emperors — was seen as woefully unsophisticated by many.