"Again, in the same books, Clement [of Alexandria] gives the tradition of the earliest presbyters, as to the order of the Gospels, in the following manner: The Gospels containing the genealogies, he says, were written first. The Gospel according to Mark had this occasion. As Peter had preached the Word publicly at Rome, and declared the Gospel by the Spirit, many who were present requested that Mark, who had followed him for a long time and remembered his sayings, should write them out. And having composed the Gospel he gave it to those who had requested it. When Peter learned of this, he neither directly forbade nor encouraged it. But, last of all, John, perceiving that the external facts had been made plain in the Gospel, being urged by his friends, and inspired by the Spirit, composed a spiritual Gospel." (Church History, 6:14)
Here we have an early source, Clement of Alexandria, who was born around the middle of the second century, reporting a tradition of "the earliest presbyters". That seems to be a significant piece of historical evidence. But the passage isn't discussed much these days. Why is that?
Many critics of Christianity have a tendency to neglect external evidence. And they don't like what Clement reports. Proponents of traditional Christianity, on the other hand, think they agree with some of what Clement says, but not all of it. Both groups, then, have reason to make little of what Clement tells us.
Let's first take the passage I've quoted at face value. And assume that Mark wasn't the third gospel to be written. Even if Clement's elders (presbyters) were wrong about the order in which the gospels were written, should we conclude that their comments on other matters have no evidential value? We don't apply that reasoning in other circumstances. If a Roman source, like Suetonius, is wrong about some things, we don't conclude that we therefore can't trust him about anything else. Sources like Clement's elders have credibility as historical witnesses even if they aren't right about everything. If we reject their testimony where other evidence suggests that they're wrong, it doesn't follow that we should also reject their testimony where other evidence doesn't suggest that they're wrong. Errors would diminish a source's general credibility and his credibility within particular categories. But a source's credibility can be diminished without being eliminated.
What I've just said assumes that we take the passage from Eusebius at face value. Should we do that, though? I don't think so. See Stephen Carlson's argument about a different rendering of the passage here and Andrew Criddle's argument about the context of the passage here. For reasons Carlson explains, the term "written first" should be translated as "openly published" instead. No other early source has Mark written after both Matthew and Luke, and Carlson's suggested reading makes more sense of the sentences that follow. Therefore, even if we assume that Mark was written prior to Matthew and Luke or before one of those two, Clement's elders aren't claiming otherwise.
But, as I explained above, the passage would have some evidential value even if we concluded that it's wrong about the order in which the gospels were composed. I'll assume something like Carlson's rendering, but some of the points I'm about to make would remain true even under the other translation.
As Criddle explains in his article, it's significant that Clement's elders identify Matthew and Luke as gospels with genealogies and refer to John as a "spiritual gospel". It seems that the issue under consideration was how the gospels portray Jesus' origins. Matthew and Luke focus on His human origin, whereas John focuses on His spiritual existence prior to the incarnation.
Notice the following implications of the passage that are relevant to the infancy narratives:
- Although Matthew and Luke aren't named as the first gospels mentioned by Clement's elders, those two gospels are by far the best candidates. As C.E. Hill explains, "no other Gospel we know of contains a genealogy of Jesus" (Who Chose The Gospels? [New York: Oxford University Press, 2010], p. 74). To propose that the elders were referring to one or two other gospels, but that those other gospels left no further trace in the historical record and were universally replaced by gospels with similar characteristics shortly afterward (Matthew and Luke), would be unreasonable. And Eusebius, who presumably knew more about Clement's context than we do, introduces Clement's comments by saying that he's addressing "the Gospels". We know how Eusebius defined that term. To assign a different definition to Clement and/or Clement's elders is baseless and a less likely reading.
- Matthew and Luke were published widely from the start, in contrast to Mark, which initially had a smaller audience.
- Matthew and Luke were published early enough to attain a widespread readership before John wrote. (John thought they had already established "the external facts" sufficiently for his readers.)
- Some scholars have argued that material like the genealogies weren't added to Matthew and Luke until later in church history, such as in response to Marcion. But Clement's elders suggest that the genealogies were part of the original gospels. John's decision to focus on Jesus' spiritual origin was based on what Matthew and Luke had already said in their gospels, such as in their genealogies.
- John knew of one or more of the other gospels. (That fact is reported by another early source, Papias, as well. See here.) It was common for the earliest patristic sources to refer to two or more of the gospels collectively as "the Gospel". It's likely that "the Gospel" John was familiar with was all three of the Synoptics combined. That's why Clement's elders don't have to specify which one is being referred to. All three of them are in view. That fact is also suggested by the widespread publication of Matthew and Luke. It's unlikely that John would have been unfamiliar with one of them or both of them if they were circulating widely. Furthermore, the reference to the genealogies in Matthew and Luke is best explained as a parallel to the more spiritual discussion of Jesus' pre-existence in the first chapter of John's gospel. Clement's elders imply that John was attempting to supplement at least one of the gospels with a genealogy and probably both of them. The best explanation for "the Gospel" that John was supplementing is that all three of the Synoptics are being referred to.
- What I've said about supplementing the other gospels should be emphasized. John held a high view of at least one of the other gospels (probably all three of them) and considered his gospel a supplement rather than a replacement. (Again, see the article on Papias linked above for similar comments from another early source. John's acceptance of the Synoptics is likewise implied by the widespread acceptance of those gospels and material within those gospels by the early Johannine churches and individuals with historical ties to John, like Papias, Polycarp, and Irenaeus. If John's gospel was meant to compete with the Synoptics, the early Johannine churches and the early historical witnesses most influenced by John don't seem to know it.)
- Clement's elders seem to view the Synoptic gospels as belonging to a historical genre, and they attribute the same view to Mark and John. They refer to Mark's intention to record Peter's teaching about "the Gospel", with the implication that Peter was a historical witness of Christ reporting historical information, like the other gospels. The elders say that John thought the earlier gospels had recorded "the external facts". It would be possible to think of Peter's teaching as fictional and to interpret "the external facts" in the sense of "the external facts within a fictional story". But neither reading is the most natural way to take the passage. Why add such qualifiers that neither the text nor the context suggests, qualifiers that would be inconsistent with what so many other early sources say about the gospels' genre? Most likely, Clement's elders are saying that all of the Synoptics belong to a historical genre, and they're attributing the same view to Mark (concerning his own gospel) and John (concerning all of the Synoptics).
Notice what we don't see in the testimony of Clement's elders. There is no late-first-century Matthean community competing with a late-first-century Lukan community, with contradictory views of Jesus' infancy that developed apart from one another in a non-historical genre, both of which were later rejected by the fourth gospel. Instead, Matthew and Luke were both published early, both had a wide initial audience, both were viewed highly by the apostle John, and both were viewed as belonging to a historical genre.
Of course, these conclusions have implications that go far beyond the infancy narratives. They're relevant to the historicity of the gospels in general.