Who wrote the Gospels?
People who doubt Christianity or the authenticity of the Bible often make a claim that nobody knows who wrote the Gospels (Matthew, Mark, Luke and John, the first four books of the New Testament that describe the earthly life and ministry of Jesus). They often hold that this alleged unknown authorship invalidates the writings somehow. While this is a nonsensical claim, nonetheless it is helpful to know that Christians can actually be quite certain of who wrote each of the four first books of the New Testament.
Matthew
This Gospel doesn’t explicitly name its author. Irenaeus quoted this Gospel as being “of Matthew” around 180 AD. The early church was in unanimous agreement that Matthew wrote this Gospel but Irenaeus was the first to explicitly claim it. The best evidence from the Gospel itself that Matthew is the author is that it’s the only Gospel that Levi the tax collector is identified as the apostle Matthew (Matthew 9:9, Matthew 10:3). At the very least, this suggests the author presents Matthew’s witness/testimony. It also shows clear evidence that the author possessed a strong command of Aramaic and Greek which would have been a prerequisite for a tax collector. It also uses more specific language over the coin used in the dispute of the tribute (Matthew 22:19) than Mark or Luke which very strongly implies that the author was conversant in the fine details of money and finance which supports the idea that the author is a tax collector.
As Jesus passed on from there, he saw a man called Matthew sitting at the tax booth, and he said to him, “Follow me.” And he rose and followed him.
Philip and Bartholomew; Thomas and Matthew the tax collector; James the son of Alphaeus, and Thaddaeus;
Show me the coin for the tax.” And they brought him a denarius.
Mark
The earliest title of this Gospel that includes “of Mark” are from around the 200s AD, although that title was likely added between 100-130 AD. Eusebius quotes Papias words to the effect that Mark, a follower of Peter, recorded stories about Jesus that Peter shared, that the stories are accurate, but not necessarily in a chronological order. Papias added that he received that information from the apostle John. Mark is mentioned 10 times in the NT in Acts and several epistles as someone who traveled with Paul and is beloved by Peter and was with him in Rome. The NT collectively describes Mark as a well connected person raised under the teachings of the apostles. It’s a trivial claim to make that he wrote this Gospel.
Luke
Luke was a traveling companion of Paul (Colossians 4:14 and others). It’s unlikely that a Greco-Roman literary work like this Gospel would have been published anonymously. Usually the name of the author, if not indicated directly in the text, was attached as a tag to the scroll. The earliest manuscript we have that bears the title “according to Luke” is from the end of the 100s AD, the heretic Marcion acknowledged Luke as the author as early as 135 AD. The Muratorian canon (185 AD) names the author of this Gospel “Luke, that physician, who after the ascension of Christ, when Paul had taken him with him as companion of his journey, composed in his own name, on the basis of report”. There is no competing tradition of authorship in the early church like could be expected if Luke’s name were attached to the Gospel on conjecture. As a minor character in the NT, there would have been other competing authorship traditions if Luke’s authorship was at all questionable.
Luke the beloved physician greets you, as does Demas.
John
The case that John wrote this Gospel is solid. He refers to himself as the “one that Jesus loved”, the brother of James and son of Zebedee, as early tradition suggests. The same tradition places John in and around Ephesus, ministering to churches in Asia Minor until his death around the end of the first century. The author would have thus been an eyewitness to much of the material he recounted and would be in a position to provide accurate information. This Gospel appears to be the first of five books John wrote in the 90s AD, the next ones being the three letters that bear his name and the book of Revelation.
Sources
This post bases much of the contained information on the CSB Apologetics Study Bible.