The title of the gospel has included the words “according to John” since at least the second century. There are several Johns mentioned in the New Testament:
- John the baptist
- John son of Zebedee, the apostle
- John the relative of Annas the high priest (Acts 4:6)
- John Mark (Acts 12:25)
- John, the father of Simon Peter (John 1:42)
John the baptist was dead before Jesus finished his ministry, so that rules him out, and John the relative of Annas was not a Christian.
Of the others, John the apostle is by far the most likely author for the following reasons.
- The author was the disciple lying next to Jesus at the last supper, and the one described as “the disciple whom Jesus loved” (John 21:20-24)
- He was one of the seven disciples who were fishing in John 21:1-8, but not Simon, Thomas or Nathanael who are named. That leaves John, James and two others.
- There was a rumour that the author would not die until Jesus returned (John 21:23), so it could not have been James who was killed not long afterwards (Acts 12:2).
- There is no mention of John by name in the gospel, whereas most of the other apostles are mentioned, including Peter, Andrew, Philip, Thomas, Nathanael, Judas Iscariot and the other Judas.
- Early writers such as Irenaeus (Against heresies, 3.12) and Tertullian say that the apostle John wrote the gospel.