John the Apostle was one of the twelve disciples of Jesus Christ and is traditionally believed to be the author of the Gospel of John, three epistles, and the Book of Revelation in the New Testament. He is often referred to as the "Beloved Disciple" and is known for his close relationship with Jesus during His ministry. John is thought to have been a fisherman by trade, working alongside his brother James before following Jesus. After the crucifixion, he played a significant role in the early Christian church, spreading the teachings of Christianity and helping to establish communities of believers.