The theory that Mark wrote his gospel first (drawing from the previously-unknown/unheard of “Q” source), with little supporting evidence, came to be spread as part of
Bismarck’s anti-Catholic ‘Kulturkampf’ policy.
Of course, Bismarck was a politician not a theologian. The universities in Germany at that time were government controlled, and anyone upholding the priority of Matthew was seen as pro-Catholic and unpatriotic at a time of nationalist fervor.
And how could Protestants in general (and Bismarck in particular) undermine the authority of the Catholic Church? Well, what is one of the primary verses pointing to the establishment of the papacy? Why, Matthew 16:18 of course: “And I say to thee: That thou art Peter; and upon this rock I will build my church, and the gates of hell shall not prevail against it.” This verse does not appear in any of the other Gospels.
So, if it could somehow be “demonstrated” that the Gospel of Matthew could not possibly have been written by Apostle Matthew (an actual eyewitness) and that therefore this verse had to have been “added in later,” what does that say about the authority of a Church based in part on that verse?
From
The Gospels Are Historical:
…Firstly, every early historian states that Matthew wrote the first Gospel. Any theory, however clever, must be doubted when it is unable to face the challenge of history.
Secondly, it conflicts with the doctrinal teaching of the Church regarding authorship.
Thirdly, the whole Markan logical edifice is balanced on a presumption. This presumption is that the Gospel of Mark was carefully thought out in the author’s room and composed by him in his best Greek style.
If a different scenario more consistent with history, doctrine and literary analysis replaces this presumption, the theory loses its foundation. …
…Those who held the view that Mark wrote third persevered in their research. From literary analysis and the ancient historians they developed the scenario of Peter giving a series of talks. In these he quoted alternatively from Matthew and Luke and thereby blended them together like two streams conflating into one. Peter’s secretary Mark, in response to repeated requests, issued copies of his unedited verbatim shorthand transcript. This is what we now know as Mark’s Gospel. According to Clement of Alexander (who lived 200 years nearer to the events than did Jerome), Peter was indifferent to its distribution until he saw its beneficial effects.
From Clement we know that Mark issued his transcript to meet an urgent demand. We can see how Luke’s Gospel could have been written pre-Mark but published after it. When Jerome wrote his: ‘Prologus Quattuor Evangeliorum’, he records that the Gospels were Published in the Matthew, Mark, Luke order. But, when writing his history: ‘Of Illustrious Men’, Jerome places them in the Matthew, Luke, Mark order (i.e. in order of writing). It should also be remembered that in Jerome’s covering letter to the Pope, regarding his vulgate version, he had to explain why he had placed the Gospels in an unfamiliar order.