I think The Gnostic Gospels being written between 250 and 350 A.D. was a problem even for what these documents claim to be because they probably made the words sounds like what they wanted to sound like rather than the true holy bible.
Something that comes to mind here in my thinking is a saying I heard once from a preacher, “the more the church is in the world, the more world gets into the church”. I really doesn’t matter how much you want to refute that or pretend it doesn’t happen, it surely does and with the dark side trying to “muddy the waters” as it were, the more time those who represent “the church” and those who study “the scriptures” have to put in twists and turns and form a labyrinth for others to become lost. The verbal histories or those who rely on verbal history passed down from generation to generation are more accurate coming from a storyteller who has had direct contact or knowledge of someone who saw the action or knew the participants and have given their abilities over to relating history as it truly happened. I have seen this so much among Native Americans and tribal history and what they pass on to their children and grandchildren is scrupulously told passed on fact – that is so very important to them. The Bible, beginning with the Old Testament, records a history that is truth and follows a steady line. Those books of the New Testament written on truths told and eye witness accounts are “set in stone”. What came after is liable to falsehoods and imagined fables. The Bible is Truth and can be relied upon.
” All scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness: 17 That the man of God may be perfect, thoroughly furnished unto all good works.” 2 Timothy 3: 16-17
Where are the primary sources for reliability in these Gnostic Gospels? There are none; therefore, they cannot be considered as a true Gospel.
I don’t think it’s a problem. There was no eyewitness accounts. They lived long after Jesus resurrection. It can not be taken seriously
The more time between accounts, the less accurate they are going to be. It’s kinda like having a witness of a car accident being questioned 5 years after the event, instead of right after the event or within a few days of the event. In the case of the witness of the car accident being questioned 5 years later, the brain may have filled in the gaps and their testimony could be tainted by others that spoke into the situation.