Arguments for the Priority of the Gospel of Mark
Over the years, three arguments have proved widely convincing for establishing Mark’s priority to Matthew and Luke:
Argument 1: Patterns of Agreement
Since the main reason for thinking that the Gospels share a common source is their verbatim agreements (i.e., someone was obviously copying someone else, since they are word for word the same), it makes sense to examine the nature of these agreements in order to decide which of the books was used by the other two. If you were to make a detailed comparison of the word-for-word agreements among these Gospels, an interesting pattern would emerge.
Sometimes all three of the Gospels tell a story in precisely the same way. This can easily be accounted for; it would happen whenever two of the authors borrowed their account from the earliest one, and neither of them changed it. Sometimes all three Gospels differ. This would happen whenever the two authors who borrowed the story each changed it, in different ways. Finally, sometimes two of the three are exactly alike, but the third differs. This would occur when both of the later authors borrowed the story but only one of them changed it; in this case one of the redactors would agree with the wording of his source, and the other would not.
In this final kind of situation, certain patterns of agreement typically occur among the Synoptic Gospels. Sometimes Matthew and Mark share the wording of a story when Luke differs, and sometimes Mark and Luke share the wording when Matthew differs. But it is rare to find Matthew and Luke sharing the wording of a story also found in Mark when Mark differs — especially anything like *lengthy* word for word agreements. Why would this be?
If Matthew were the source for Mark and Luke, or if Luke were the source for Matthew and Mark, you would probably not get this pattern. Look at it like this: If, as I’m arguing, both Matthew and Luke used Mark, then sometimes they would both reproduce the same wording. That’s why all three sometimes agree. Sometimes they would both change the wording for reasons of their own. That’s why all three sometimes differ. Sometimes Matthew would change Mark’s account when Luke left it the same. That’s why Mark and Luke sometimes agree against Matthew. And sometimes Luke would change Mark’s account when Matthew left it the same. That’s why Matthew and Mark sometimes agree against Luke.
The reason then that Matthew and Luke rarely agree against Mark in the wording of stories found in all three is that Mark is the source for these stories. Unless Matthew and Luke accidentally happen to make precisely the same changes in their source (which does happen on occasion, but not commonly and not in major ways), they cannot both differ from the source and agree with one another. The fact that they rarely do differ from Mark while agreeing with one another indicates that Mark must have been their source.
Argument 2: The Sequence of Narrative
One of the most striking aspects of the Synoptic Problem (that’s the technical term for explaining all the similarities and differences among the three Synoptic Gospels) is that even though Matthew and Luke do not often agree together against Mark in the wording of stories that all three of them share, they do extensively agree in the wording of passages that are not found in Mark. For example, both Matthew and Luke have versions of the Lord’s Prayer and the Beatitudes. Most, but not all, of these other passages are sayings of Jesus. Later we will pursue the evidence that suggests that Matthew and Luke must have gotten these from the source scholars call Q. What is significant at the present juncture is that even the materials not found in Mark suggest that Mark was a source for Matthew and Luke. This conclusion is based on the sequence of the stories found in these other two Gospels.
Matthew and Luke often present the stories of their Gospels in the same sequence (Jesus did this, then he did that, then he said this, and so on). What is odd is that when they do preserve the same sequence, it is almost always with stories that are also found in Mark. The other materials (mainly sayings) that the two Gospels share—that is, those not found in Mark—are in virtually every instance located in different places of their narratives.
But why would that be? The best explanation is that Matthew and Luke each used Mark as one of their sources and also had a different source that they plugged into the narrative framework of Mark at different places. That is to say, not having any indication from Mark’s Gospel where traditions like the Lord’s Prayer or the Beatitudes would have fit into the life of Jesus, each author put them in wherever he saw fit. Almost never, however, did this other material go in at the same place.
This curiosity of sequence can scarcely be explained if Mark were not one of the sources for Matthew and Luke. Imagine for a moment a different scenario, that Matthew were the source for Mark and Luke. In this hypothetical case, Mark must have decided to remove some of Matthew’s stories (since his Gospel is much shorter than Matthew’s). Many of these Matthean passages that Mark omitted, however, were retained by Luke. But when Luke copied Matthew, why would he have rearranged precisely these passages? That is to say, why would Luke have rearranged only those traditions that Mark did not bother to copy, while keeping the stories that Mark did copy in the same sequence?
It is almost impossible to think that Luke worked this way (or Matthew, if Luke were the source for both him and Mark). Therefore, the additional traditions of Matthew and Luke that occur in different places in their narrative indicate that Mark was one of their sources, into which they both inserted these other passages.
Argument 3: Characteristics of the Changes
One final argument that is typically advanced for Markan priority is that the kinds of differences in wording that one finds among the three Gospels suggest that Matthew and Luke used Mark as a source. Some of these arguments, again, get rather technical; here I will simply explain the issues in general terms.
Sometimes Mark uses a Greek style of writing that is somewhat awkward or not aesthetically pleasing, sometimes he uses unusual words or phrases, and sometimes he presents difficult ideas. In many instances, however, these problems are not found when Matthew or Luke narrates the same stories. This difference suggests that Mark was the earliest of the three to be written. That is to say, it would be difficult to understand why Mark would introduce awkward grammar or a strange word or a difficult idea into a passage that originally posed no problem, but it is easy to see why Matthew or Luke might have wanted to eliminate such problems. It is more likely, therefore, that Mark was first and that it was later modified by one or both of the other authors.
A final and related point is that Mark is the shortest of the three Synoptics. If the author had used one of the others as his source, why would he have eliminated so many good stories? Did he want to produce a shorter version of the life of Jesus? This may sound plausible, but a close examination of the Gospel texts shows that it can’t be right: in almost every instance that Mark and Matthew tell the same story, Mark’s is longer. Mark doesn’t appear, then, to be the work of a condenser. The conclusion that most scholars have reached, therefore, since the nineteenth century is that Mark’s Gospel is the first to have been written, and that it was used independently by both Matthew and Luke.