The letters of First, Second and Third John were written by John, one of the apostles of Jesus Christ. John was the son of Zebedee and Salome and the brother of James (Matthew 4:21; Matthew 27:55,56; Mark 15:40,41). Before John became a follower of Jesus, John was a fisherman (Luke 5:7-10). He and his brother James were among the first disciples chosen by Jesus (Matthew 4:21,22). He was among the twelve who were selected from all the disciples to be apostles (Luke 6:13-16).

John, James and Peter were special friends of Jesus (Mark 5:35-42; Matthew 17:1-9; 26:36, 37). On one occasion Jesus called James and John the "sons of thunder" (Mark 3:17; Luke 9:51-56). John referred to himself in the Gospel of John as "the disciple whom Jesus loved" (John 20:2; 21:20, 24). When Jesus was dying on the cross, he entrusted the care of His mother to John (John 19:26, 27). It is commonly believed that John was the only one of Jesus’ apostles to die a natural death. The rest were killed because of their faith.

First John

Early Christian writers such as Irenaeus and Clement of Alexandria said that John moved to Ephesus after Jerusalem was destroyed in A.D. 70. The apostle Paul had established many churches in Asia where Ephesus was located. John addressed the book of Revelation to "the seven churches of Asia."  Irenaeus wrote "... the church in Ephesus, founded by Paul, and having John remaining permanently among them until the time of Trajan, is a true witness of the tradition of the apostles." If John lived until the time of Trajan who ruled from A.D. 98 to A.D. 117, he must have been about one hundred years old when he died. First John was likely written between A.D. 85 and A.D. 90.

False teachers had invaded the churches. John wrote to refute them. These false teachers denied that Jesus had come as a human being (1 John 1:2; 2:22, 23; 4:1-3). They were later called "Gnostics" because they claimed to have special knowledge. "Gnostic" comes from the same Greek word from which we get the word for "knowledge." The Gnostics taught that flesh is evil. If flesh is evil, then they reasoned, the Son of God could not have been born of a woman. Some even believed that Jesus did not have a body of flesh, but only seemed to have a physical body. Others said Jesus was just an ordinary man. The "Christ" came upon the man, Jesus, when he was baptized and left Him shortly before He was crucified.

In the first chapter of First John, John gives his eyewitness testimony that Jesus had come in the flesh (1 John 1:1-4). He then points out that our fellowship with God is possible only if we walk in the light (1 John 1:7-10). In chapter two, John warns of the coming of antichrists. Whoever denies that Jesus has come in the flesh is an antichrist (1 John 2:18-29). In chapter three, John teaches that Christians do not live a life of continual sinning (1 John 3:1-10). He also discusses the meaning of real love (1 John 3:11-24). John begins chapter four by telling Christians that they must not believe every teacher but must put them to the test (1 John 4:1-6). Then he discusses more about love. In chapter five, John teaches that eternal life is found only in Jesus Christ (1 John 5:4-13). He concludes his first epistle with a discussion of prayer and forgiveness (1 John 5:14-21).

Second John

Second and Third John are the two shortest books in the New Testament. John calls himself "the elder" in the beginning of these letters. This probably refers to the fact that he was now a very old man. Second John is addressed to "the elect lady and her children."  Some think "the elect lady" refers to a church and "her children" refers to the members of the church. It is more likely that John was writing to a Christian woman. John had found her children walking in the truth. He writes to commend her for this. John also teaches the importance of love. Christians must love one another. If we love God we will also keep His commandments.

John next warns the Christian woman of false teachers who deny that the Son of God came into this world as a man. One who denies that Jesus has come in the flesh, as the Gnostics did, is a "deceiver and an antichrist."  John also points out the importance of remaining in the true teaching. If one does not remain in the truth, he does not have God! If one does not have God, he is lost! If one remains in the true teaching, he is in fellowship with both God the Father and His Son, Jesus Christ. Therefore, he is saved!

John also warns Christians that they must not support false teachers in any way. If a teacher does not teach the truth, he must not even be given hospitality in our homes. If one helps a false teacher in any way, he becomes just as guilty as the false teacher.

Third John

The short epistle of Third John mentions three men in the church. John commends two of them and condemns one. John is writing to a godly Christian whose name is Gaius. Gaius had showed hospitality to brethren and to strangers and was commended for it. John had written to the church where Gaius was a member. Diotrephes, a member of the church, loved to have preeminence. He would not receive John and spoke malicious words against him. He would not show hospitality to brethren and opposed others who did. Another brother in the church was commended by John. Demetrius was a member who had "a good testimony from all, and from the truth itself."

Jude

Jude was a brother of James. It is believed that this is James who was one of the younger (half) brothers of Jesus. Therefore, Jude was also a (half) brother of our Lord (Matthew 12:46,47; Matthew 13:53-56; John 7:1-5; Acts 1:14). Jude had planned to write a letter concerning the salvation which all Christians enjoy in common. However, the presence of false teachers in the church caused him to change what he wrote. Instead, he urged the brethren to "contend earnestly for the faith which was once for all delivered to the saints" (Jude 3). Jude is a book which teaches Christians that they must always be on guard against those who would destroy their faith and lead them astray.