When churches received each Gospel, they also received information about that Gospel’s origins, telling them whose eyewitness testimony this Gospel represented. Because they received clear oral traditions when they received each book, when Christians began adding titles to these manuscripts, every congregation connected each Gospel to the same author.
So who really wrote the Gospels? How do we know that Matthew, Mark, Luke, and John dictated the books that bear their names? According to skeptics, these four first-century personalities had little or nothing to do with the four New Testament Gospels. One scholar of the more skeptical sort has described the process in this way:
[The New Testament Gospels] were written thirty-five to sixty-five years after Jesus’ death, … not by people who were eyewitnesses, but by people living later. … Where did these people get their information from? … After the days of Jesus, people started telling stories about him in order to convert others to the faith.[i] … When … Christians recognized the need for apostolicauthorities, they attributed these books to apostles (Matthew and John) and close companions of apostles (Mark, the secretary of Peter; and Luke the traveling companion of Paul).[ii]
In other words, Christians didn’t connect the Gospels to Matthew, Mark, Luke, and John because these individuals actually wrote the Gospels. Early believers fabricated these connections to make the documents seem more authoritative.
Now, it is indeed quite likely that the earliest Gospel manuscripts didn’t include titles in the manuscripts themselves (though the possibility titles on tabs hanging from manuscripts or inscribed at the end of each book should not be ruled out). But there’s a serious problem with the skeptics’ reconstruction.[iii] By the late first and early second century, the Gospels had spread throughout the Roman Empire.[iv] If second-century Christians had simply added names to each Gospel to make that Gospel seem authoritative, what would have happened? (Remember, there was no centrally-recognized authority to force congregations to connect a certain name to each Gospel—no executive director, no denominational board, no international convention of Christians.[v] And it wasn’t as if one pastor could stop by an office and email fellow-pastors about how to name a certain Gospel!)