Papias is an important figure in determining how it is we know what we know about the authors of the Gospels. This is a problem that is somewhat difficult for contemporary readers to understand, largely because metadata is something we deal with on a regular basis, so often that we often fail to recognize its problematic nature in ancient texts. When we look at book, metadata is all over the place. The book greets us with a title and author on its title page and often the title and author and publisher are printed on the spine of the book (or book cover) as well when we look at it. The book contains a copyright page that gives in detail the ISBN number for tracking as well as information about the copyright date or number of pages or how the book is labeled according to the Library of Congress or some other system, and there are often detailed indices and footnotes or endnotes and biographical information about the author and sometimes lists of books that the author has previously written. All of this data is missing when we look at the writings of the ancient world.
This is perhaps not too surprising if we look at it closely enough. The books of the Bible and the writings of the Apostolic Fathers in the century or so after the Bible was written were not published by the ancient world equivalent of our large publishing houses or even vanity presses. By and large, they were self-published affairs. About half of the New Testament, for example, is made up of the personal mail of various Apostles and their associates (mostly Paul, but also John, Peter, James, and Jude). Yet, just as is the case for our letters, the letters of the Apostles are easy enough to label by author even if some scholars continue to doubt the legitimacy of Ephesians or 2 Peter or the pastoral epistles, and this is with the information of the writer and the recipients of the letters intact within the writings themselves as they they are for epistles in general. Metadata is a much more serious issue when one looks at the Gospels because the Gospels were not a form of literature that included the sort of metadata that we take for granted in our contemporary books. Moreover, two of the authors of the Gospels (Matthew and Mark) wrote nothing else that we can compare to the Gospels on stylistic grounds the same way that Luke-Acts and the writings of John are easy to compare with each other on textual grounds .
It is fortunate, therefore, that we have the writings of Papias to help us understand the differences between Matthew and Mark as Gospels. Writing in the late first to early second century, within the lifetime of people who knew the Apostles firsthand (and with himself an associate of John’s), Papias has this to say about the first two Gospels: “Mark having become the interpreter of Peter, wrote down accurately whatsoever he remembered. It was not, however, in the exact order that he related the sayings or deeds of Christ. For he neither heard the Lord nor accompanied Him. But afterwards, as I said, he accompanied Peter, who accommodated his instructions to the necessities [of his hearers], but with no intention of giving a regular narrative of the Lord’s sayings. Wherefore Mark made no mistake in thus writing some things as he remembered them. For of one thing he took especial care, not to omit anything he had heard, and not to put anything fictitious into the statements (14).” And of Matthew Papias writes: “Matthew put together the oracles [of the Lord] in the Hebrew [Aramaic?] languag, and each one interpreted them as best as he could (14).”
Papias, therefore, shows himself to be a conscientious writer about the Gospels, and it is fortunate that we have surviving these comments about the first two Gospels, at least. Matthew was said to have been the secretary of the Gospels, writing down the oracles of the Lord which were then interpreted by others and used later in (in either Greek or Aramaic or both) his own Gospel account. Thus Papias gives us the first recorded comments we have of the mythical source Q of the sayings of Jesus Christ, and lo and behold Papias records Matthew as having been the secretary among the Apostles and recording down what Jesus taught for others to use as a fair record. Likewise, Papias’ statements about Mark are perfectly sensible in light to the fact that Mark was a youth at the time of Jesus’ preaching and while he was definitely early associated with the Apostles (being a relative of Barnabas and an early and late associate of Paul), he makes no claims of having followed Jesus during his ministry and his own account of fleeing naked from the Garden of Gethsemane is of a piece of modesty and self-effacement typical of the earliest New Testament writings. Here Papias provides information about the authorship of Matthew and Mark that we would not have by looking at the Gospels alone.
And this indicates the nature of the metadata problem for these texts as a whole. The original Gospels did not include their authors’ names, and the authors themselves were modest (both Luke and John are possible to identify through process of elimination in their writings, but it takes some work) and not the sort to brag about themselves. Yet with the early copies of the manuscripts of the Gospels went various traditions and oral statements that provided context. Papias, fond of hearing and also of recording down what he had heard from associates of the earliest Christians, records these traditions passed along with the text down, and later writers (fortunately) saw enough that was worthwhile in these comments to record them for our benefit, such that we have the Gospels with their authors and can know at least something about the circumstances in which they were written, and the reasons why the Gospels differ as they do in terms of their focus and perspective. When we see Matthew and Luke as careful chroniclers and Mark writing the perspective of Peter and focusing on the action of Jesus Christ that Peter’s early audience heard with pleasure and John as writing after the other Gospels and filling in some of the gaps in the narrative with his own memories and aimed at heresies during his own time, we can understand something of the context in which the Gospels were written and copied. And in that understanding, we owe Papias a great deal as an early recorder of that context for our benefit.
 See, for example: