Introduction to I John
The three epistles of John nowhere include John’s own name as writer. Nevertheless, the concepts and vocabulary are all so similar to those of the gospel of John, and even to those in the book of Revelation, that there should be little doubt that the same writer wrote all five books, and that that writer was the Apostle John, son of Zebedee, brother of James, and “beloved disciple” of Jesus.
In reference to vocabulary, such words as know, love, light, truth, abide, witness, keep, overcome, eternal, and many others occur in John’s gospel more than in any other gospel. Likewise, they all occur in the epistle of I John more than in any other epistle. These very words represent the great themes of both the gospel and the epistles of John. Furthermore, the unbroken tradition of the ancient church is that the Apostle John wrote both the gospel and the three epistles. There is, therefore, every reason to accept all of these as authentic and inspired writings of John.
As Jesus had implied (John 21:22), John long outlived all the other apostles. He is last mentioned in Acts in connection with the martyrdom of his brother James (Acts 12:2), and last mentioned in the other epistles in connection with Paul’s visit to Jerusalem (Galatians 2:9). The rest of his life was undoubtedly marked by active ministry, but little is known of it except that, according to the uniform tradition of the early church fathers (such as Polycarp, Irenaeus, Papias, and others) the last decade or more of John’s life was centered in Ephesus, from which he kept in touch with many of the churches in Asia, probably especially those referred to by him in Revelation 2 and 3. It was there, according to the same church fathers, that he wrote I John and, indeed, probably all four of his other books. All were written after the other eleven apostles had died, probably by martyrdom. Furthermore, the fall of Jerusalem in A.D. 70 was also past history when John wrote. Neither John’s gospel, nor his first epistle, therefore, was meant either for the Jews or for a specific church, but rather for all people everywhere, though probably I John was intended especially for the churches in Asia, centered around Ephesus, among whom John was ministering. This was all probably in the decade from A.D. 85 to 95.
As the gospel of John was written specifically to stress the deity of Christ and to win unbelievers to saving faith in Him (John 20:31), so the epistle of I John was written to stress the full (though sinless) humanity of Jesus and to assure believers of the certainty of their gift of eternal life (I John 5:11-13).
A further purpose of I John was to refute those Christians who were seeking to accommodate Gnostic philosophies and practices into their Christian faith and life. Gnosticism was a pagan evolutionary philosophy which was in existence well before the birth of the Lord Jesus Christ but, by the middle of the first century many Christians were compromising with it. There were many varieties of Gnostics, but all rejected the concept of special creation by the transcendent God of the Bible, and either the true deity or true humanity of the Lord Jesus Christ. Further, their practice involved either extreme asceticism within one group of Gnostics or anti-nomianism and libertinism among other groups. In his epistle, John was combating all these false teachings. The name “Gnostic” came from gnosis, meaning “knowledge,” since most Gnostics claimed to have occult knowledge of deep truths, amounting essentially to a form of mystical evolutionary pantheism.
This may well have been one reason for John’s strong emphasis on knowledge in his epistle, showing that the believer in Christ has genuine knowledge of salvation through faith in the atoning sacrifice of the God/man Jesus Christ. The word “know,” for example, occurs some thirty-eight times in I John, as translations of either ginosko or eido, both of which mean “know for certain.” Among other things, John lists several criteria by which the believer may assure himself that his salvation is genuine, and therefore certain and eternal (e.g., I John 2:3; 3:14; 5:13).
The theme of love is also very prominent in I John. The word “love” (Greek agape, agapao, or agapetos) occurs over fifty times in these five chapters. “Truth” occurs ten times and “life” fifteen times. Also of interest is the fact that “antichrist” occurs five times in John’s epistles, but nowhere else in the New Testament, even though the theme of the coming Antichrist is common throughout the Bible. The closing word in I John is a command to believers to keep away from idols (I John 5:21).