The epistle’s title has always been “1 John.” It is the first and largest in a series of 3 epistles that bear the Apostle John’s name. Since the letter identifies no specific church, location, or individual to whom it was sent, its classification is as a “general epistle.” Although 1 John does not exhibit some of the general characteristics of an epistle common to that time (e.g., no introduction, greeting, or concluding salutation), its intimate tone and content indicate that the term “epistle” still applies to it.

Although he was greatly advanced in age when he penned this epistle, John was still actively ministering to churches. He was the sole remaining apostolic survivor who had intimate, eyewitness association with Jesus throughout His earthly ministry, death, resurrection, and ascension. The church Fathers (e.g., Justin Martyr, Irenaeus, Clement of Alexandria, Eusebius) indicate that after that time, John lived at Ephesus in Asia Minor, carrying out an extensive evangelistic program, overseeing many of the churches that had arisen, and conducting an extensive writing ministry (e.g., epistles, The Gospel of John, and Revelation). One church Father (Papias) who had direct contact with John described him as a “living and abiding voice.” As the last remaining apostle, John’s testimony was highly authoritative among the churches. Many eagerly sought to hear the one who had first-hand experience with the Lord Jesus.

Ephesus (cf. Acts 19:10) lay within the intellectual center of Asia Minor. As predicted years before by the Apostle Paul (Acts 20:28–31), false teachers arising from within the church’s own ranks, saturated with the prevailing climate of philosophical trends, began infecting the church with false doctrine, perverting fundamental apostolic teaching. These false teachers advocated new ideas which eventually became known as “Gnosticism” (from the Gr. word “knowledge”). After the Pauline battle for freedom from the law, Gnosticism was the most dangerous heresy that threatened the early church during the first 3 centuries. Most likely, John was combating the beginnings of this virulent heresy that threatened to destroy the fundamentals of the faith and the churches (see Interpretive Challenges).

Gnosticism, influenced by such philosophers as Plato, advocated a dualism asserting that matter was inherently evil and spirit was good. As a result of this presupposition, these false teachers, although attributing some form of deity to Christ, denied his true humanity to preserve Him from evil. It also claimed elevated knowledge, a higher truth known only to those in on the deep things. Only the initiated had the mystical knowledge of truth that was higher even than the Scripture

Instead of divine revelation standing as judge over man’s ideas, man’s ideas judged God’s revelation (2:15–17). The heresy featured two basic forms. First, some asserted that Jesus’ physical body was not real but only “seemed” to be physical (known as “Docetism” from a Gr. word that means “to appear”). John forcefully affirmed the physical reality of Jesus by reminding his readers that he was an eyewitness to Him (“heard,” “seen,” “ handled,” “JesusChrist has come in the flesh”—1:1–4; 4:2,3). According to early tradition (Irenaeus), another form of this heresy which John may have attacked was led by a man named Cerinthus, who contended that the Christ’s “spirit” descended on the human Jesus at his baptism but left him just before his crucifixion. John wrote that the Jesus who was baptized at the beginning of His ministry was the same person who was crucified on the cross (5:6).

Such heretical views destroy not only the true humanity of Jesus, but also the atonement, for Jesus must not only have been truly God, but also the truly human (and physically real) man who actually suffered and died upon the cross in order to be the acceptable substitutionary sacrifice for sin (cf. Heb. 2:14–17). The biblical view of Jesus affirms His complete humanity as well as His full deity.

The gnostic idea that matter was evil and only spirit was good led to the idea that either the body should be treated harshly, a form of asceticism (e.g., Colossians 2:21–23), or sin committed in the body had no connection or effect on one’s spirit. This led some, especially John’s opponents, to conclude that sin committed in the physical body did not matter; absolute indulgence in immorality was permissible; one could deny sin even existed (1:8–10) and disregard God’s law (3:4). John emphasized the need for obedience to God’s laws, for he defined the true love of God as obedience to His commandments (5:3).

A lack of love for fellow believers characterizes false teachers, especially as they react against anyone rejecting their new way of thinking (3:10–18). They separated their deceived followers from the fellowship of those who remained faithful to apostolic teaching, leading John to reply that such separation outwardly manifested that those who followed false teachers lacked genuine salvation (2:19). Their departure left the other believers, who remained faithful to apostolic doctrine, shaken. Responding to this crisis, the aged apostle wrote to reassure those remaining faithful and to combat this grave threat to the church. Since the heresy was so acutely dangerous and the time period was so critical for the church in danger of being overwhelmed by false teaching, John gently, lovingly, but with unquestionable apostolic authority, sent this letter to churches in his sphere of influence to stem this spreading plague of false doctrine.