John (not to be confused with John the Baptist), was one of the twelve Apostles of Jesus. He was the son of Zebedee (Mark 1:1-20) and the brother of James. Jesus nicknamed them the “Sons of Thunder” (Mark 3:17). John’s mother was Salome, a sister of Mary, making him a cousin of Jesus (compare Mark 15:40, Matthew 27:56, & John 19:25). He was a fisherman, along with James, Simon Peter, and Andrew. All four of them left their fishing nets to become a disciple of Jesus. Peter, James, and John became the three closest friends of Jesus.
John is second only to Paul as to the number of books authored in the New Testament. John wrote the Gospel of John, 1-3 John, and Revelation. His Gospel account was written around ad 85, the last of the four Gospels written. The epistles of 1-3 John were letters written shortly after his Gospel, intended to be circulated among all Christians. Revelation was written around ad 95 and is an apocalyptic vision from Jesus Christ. As an apocalyptic writing, Revelation is highly symbolic and focuses on the end times.
After the death and resurrection of Jesus, John is believed to have moved to Ephesus with Mary to honor the request of Jesus to care for His mother. John was later exiled to the nearby island of Patmos from around ad 90-95. John is the only one of the Apostles to live a long life, dying a natural death rather than as a martyr. December 27th is the festival day set aside for John in the west.
The purpose of John’s writings are clear: “These have been written so that you may believe that Jesus is the Christ, the Son of God, and that by believing you may have life in His name” (John 20:31).