Answering the Synoptic Problem in Relation to Mark as Source Material
I’m answering a bizarree critique of the Gospel which posits Mark as the only source material for the other gospels.
First, there is zero way to prove that all the gospels are copies of Mark. Otherwise they would be copies of Mark–there would be zero diversity in perspective. That Mark influenced other authors isn’t all that unusual. All books are written in the context of community and culture. Thats what a community and culture is by definition. And cross-references are an intrinsic part of Biblical literature.
The heuristic “partial similarities in histories are untrue” is the hidden premise in your argument. Its false on its face. Its not a heuristic that any history could realistically withstand. Right, the best in academic histories uses citation. This was their version of citation.
That they re-mixed some of Mark’s material to provide more context to their own writing is a benefit, not a subtraction.
“If Matthew, Mark, and Luke did not use a “Q” document, why are their Gospels so similar? There are several possible explanations. It is possible that, whichever Gospel was written first (possibly Mark, although the church fathers reported that Matthew was written first), the other Gospel writers had access to it. There is absolutely no problem with the idea that Matthew and/or Luke copied some text from Mark’s Gospel and used it in their Gospels. Perhaps Luke had access to Mark and Matthew and used texts from both of them in his own Gospel. Luke 1:1–4 tells us, “Many have undertaken to draw up an account of the things that have been fulfilled among us, just as they were handed down to us by those who from the first were eyewitnesses and servants of the word. Therefore, since I myself have carefully investigated everything from the beginning, it seemed good also to me to write an orderly account for you, most excellent Theophilus, so that you may know the certainty of the things you have been taught.”
Ultimately, the Synoptic “Problem” is not as big a problem as some try to make it out to be. The explanation as to why the Synoptic Gospels are so similar is that they are all inspired by the same Holy Spirit and are all written by people who witnessed or were told about the same events.”
Finally if you want a long explanation of the Synoptic Problem from Daniel Wallace you can read here.