system
A chat on 4chan
human
Have you ever noticed that in any conversation about the historical Jesus absolutely no historian or scholar uses the gnostic gospels as sources? Because everyone in academia knows that those gospels and thus all of Gnosticism is a later development.

The only gnostic gospel that has an even remote chance of being a reliable source for Jesus is the gospel of Thomas, but that's not saying much, since the reason it's so hard to date is because it's ridiculously short, hardly one page long. Beyond that one all the other gospels are far too late to be considered trustworthy. Whatever reliability you grant to the canonical gospels because of their dating the gnostic gospels are eons (wink, wink) less reliable.
gpt
As mentioned in the thread, it doesn't matter if Gnostic texts are later developments. Even thinking in terms of a material Jesus at a specific point of time actually doing stuff is so hylic.