A couple of intriguing ancient manuscript fragments, The Secret Gospel of Mark and the Egerton Papyrus are even better examples. One reads them with a sense of deja vue: the individual sentences are all familiar from the gospels, but they never appear in the gospels in precisely these combinations. The puzzle has been put together a different way. Mark may have followed this "jigsaw puzzle" method in assembling his gospel.
On the other hand, his narrative moves so fast, spending virtually no time on scenery, characterization, description, that it reads almost like an abridgement of some earlier, more fulsome document now lost. There's probably no way to tell for sure. We have the same problem with An Ephesian Tale, a second century C.E. (= A.D.) novel written by Xenophon of Ephesus. Scholars still debate whether Xenophon was just a hasty, sketchy writer, or whether he had for some reason condensed a longer original into a sort of Reader's Digest version.
Matthew and Luke both independently made their own redacted versions of Mark, preserving by far most of his original verbatim, cutting superfluous, confusing, or embarrassing bits here and there. Matthew and Luke each had on hand another document that must have been as popular and well-known as Mark's Gospel, and that one, now lost, scholars call simply "Q," for Quelle, German for "source" [it was German scholars who first figured all this out]. It was a lengthy compilation of sayings of Jesus, with only a few short pieces of narrative. There was no crucifixion or resurrection in Q. The Gospel of Thomas, one of the great number excluded from the official list of the churches, is very much like Q in these respects: mainly sayings with no narrative context, no cross, no resurrection. A lot like the Book of Proverbs, actually.
How do we know there was such a thing as the Q Gospel? It seems a safe bet, since there is quite a bit of material, a number of sayings, that both Matthew and Luke have in their gospels which they couldn't have gotten from Mark, since Mark doesn't have it. When we look carefully at the differences between Matthew, Luke, and Mark in those places where all three overlap, we soon get an idea of the ways, stylistically and theologically, that both later gospel writers made changes in their common source-document Mark. Then when we take a look at how Matthew and Luke differ in their wording of non-Markan sayings they share in common, we can hardly escape the impression that here, too, Matthew and Luke were working on a prior document, one independent of Mark. And this is what we dub "Q" for want of any information of whatever title it may actually once have had.
Matthew and Luke each have a good deal of "extra" material of their own, i.e., stories or sayings not to be found in Mark or in Q. Where did Matthew and Mark come by this material? There are several possibilities. Each may have had access to traditional orally transmitted sayings or stories (such material continues, in fact, to surface, quoted by various Christian writers through the next couple of centuries) that the other had never heard of. Of some of it may have been included in Q but picked out for use by only either one of the evangelists (= gospel writer). Or Matthew and Luke may have separately made up various new stories and sayings and attributed them to Jesus. This sort of thing was quite common in early Christian gospels including the Pistis Sophia, The Dialogue of the Savior, The Apocryphon of James, The Gospel of Mary Magdalene, etc. I think that very much of the uniquely Matthean and Lukan material is their own invention. Usually their style and their theology have left fingerprints all over the text at these points.
A comprehensive comparison of the gospels suggests to most New Testament scholars that it is possible to draw up a profile of each evangelist based on the tendency or pattern of changes he made in the earlier gospels he used in producing his own redacted version. By seeing what Matthew added to Mark or omitted from Mark, or what he tried to "clarify" (really, to correct) in Mark's text so that Matthew's own readers might not be left with the "wrong" idea. You can catch the drift of Luke's changes to Mark (or Q) in the same way, and it turns out that Matthew and Luke's beliefs and agendas differed from one another as much as either differed from Mark. Of course there must have been more agreement than disagreement, or Matthew would never have used Mark in the first place. Not enough of it would have suited him. So with Luke. And Matthew and Luke cannot have been drastically different, or they never would have used the same sources.
John, on the other hand, must have found himself a lot less satisfied with Mark (or the other two, all of which he may had in front of him as he wrote) since he did pretty much a wholesale rewrite. The Fourth Gospel is so radically different from the other three in events, order of events, the type of teaching attributed to Jesus, etc., that one does not at first notice that they have much specific in common at all. A closer scrutiny does, however, imply that John knew Matthew, Mark, and Luke. He never simply reproduces their wording, as Matthew and Luke often reproduce Mark's. Sometimes John seems to have been acquainted with another version of a story or a saying and preferred it to Mark's or Luke's. Sometimes he seems to have been freely creating out of his own head (or, as he put it in John 16:14, from the inspiration of the Parakletos of Jesus). Other times he actually seems to be referring to an earlier gospel's version but only by way of refutation.
An illustrative example might be appropriate at this point. Both will be instances of later evangelists smoothing out Christological "rough spots" in their sources. In other words, places where the earlier gospel did not presuppose such an exalted and superhuman understanding as the later writers themselves held.
Let's take the baptism of Jesus at the Jordan River by John the Baptizer. As we read the story in Mark 1:2-11, the scene presents several elements that made later orthodoxy cringe. For one thing, what's he doing there in the first place? It's a baptism of repentance, for Pete's sake! Jesus? Repenting? That's pretty much like going forward at a Billy Graham rally. Mark apparently had no problem with the idea. He had as yet no dogma of Jesus' absolute sinless perfection to worry him. Similarly, in Mark 10:17-22, an inquirer approaches Jesus with polite flattery, "Good rabbi, what must I do to inherit eternal life?" With the nit-picking correctness of the holy man ever on guard against pride, Jesus prefaces his answer with this humble disclaimer: "Why do you call me good? No one is good but God alone."
Matthew distinctly did not like what he read here. For Jesus shares the perfect goodness of God, so he rewrites the same scene (Matthew 19:16-22) so as to circumvent Jesus' denial of having Godlike goodness. Now the inquirer asks him, "Rabbi, what good thing must I do to inherit eternal life?" Jesus' reply? "Why do you--ask me about what is good?" There's nobody here either affirming or denying the goodness of Jesus. Problem solved! And this is a consistent pattern with Matthew. When he comes to certain points in Mark he flinches and gets out the white-out.
So how would we expect Matthew to handle the baptism of Jesus? We would expect some kind of abrupt, even clumsy alteration to allay his readers' fear of heresy. And that's exactly what we do in fact find. As Jesus is about to be baptized, "John tried to prevent him, saying. 'It is I who need to be baptized by you! And you come to me?' Jesus reassured him, 'Let it be so, for we must fulfill all the obligations of righteousness.'" The reasoning attributed to Jesus here seems a bit vague, but one thing is clear: whatever the reason Jesus was there to be baptized, it wasn't because he was a sinner pledging to change his ways! And that's the only point Matthew wished to make.
Another sticking point with the Markan baptism story was the mere fact that Jesus had come to receive spiritual service from John, implying he viewed John as a guru superior to himself. As we just saw, Matthew took care of that one, too. Not only does Matthew's John the Baptizer tell Jesus that Jesus doesn't need his baptism; he says that he himself stands in need of Jesus' spiritual empowerment. Luke had the same problem, and his way of dealing with it is scarcely more felicitous than Matthew's crowbar approach. He relates the facts about John's baptizing ministry (Luke 3:1-18), then concludes it with John's arrest by the minions of Herod Antipas (3:19-20), which brings the Baptizer's public activities to an end. Only then does Luke get around to telling the reader about Jesus' baptism, and that in a brief analepsis