from what i remember, the 4 gospel books that are in the new testament were written between 40-75 AD. its known that there a bunch of other "gospel" texts that were written, but werent included in what is now the bible b/c they were found to be written beyond that time frame (i.e. 100+AD). if this thing was written even as early as 150 AD, i wouldnt have a hard time assuming it would have some crucial differences along w/ less credibility. plus the fact that national geographic says it came from w/in the religious group, the Gnostics, which had a totally different worldview from the early church.

dont ask me how i know all this h: