John the Apostle was one of the Twelve Apostles of Jesus. Christian tradition identifies him with the authors of several New Testament works, including the Gospel of John. Some modern scholars distinguish at least three different authors. The creator of the Gospel of John and the First Epistle of John is known as John the Evangelist, John the Theologian or John the Divine.

John is traditionally held to be the author of five books of the New Testament, including the Gospel of John. However, almost all modern critical scholars place the writing of the final edition of John at some time in the late first or early second century. See Authorship of the Johannine works.

Catholic/Orthodox tradition says that he and the Virgin Mary moved to Ephesus, where both eventually died. Many Evangelical and other scholars question this, especially due to the advanced age which Mary would have reached by this time. Some believe, however, that there is support for the idea that John did go to Ephesus and from there wrote the three epistles traditionally attributed to him. John was allegedly banished by the Roman authorities to the Greek island of Patmos, where some believe that he wrote the Book of Revelation. According to Tertullian (in The Prescription of Heretics) John was banished (presumably to Patmos) after being plunged into boiling oil in Rome and suffering nothing from it. It is said that the entire colosseum were converted to Christianity upon witnessing this miracle.

Christians largely believe this to be the fulfillment of Christ's word's in John 21:23 and Matthew 16:28, concerning John being kept alive until seeing Christ's kingdom coming. Indeed in the Book of Revelation John records seeing Christ's kingdom coming, revealed through a series of visions received by him on the Island of Patmos.