1Whoever believes that Jesus is the Christ has been born of God. Whoever loves the Father also loves the child who is born of him. 2By this we know that we love the children of God, when we love God and keep his commandments. 3For this is loving God, that we keep his commandments. His commandments are not grievous. 4For whatever is born of God overcomes the world. This is the victory that has overcome the world: your faith. 5Who is he who overcomes the world, but he who believes that Jesus is the Son of God?
6This is he who came by water and blood, Jesus Christ; not with the water only, but with the water and the blood. It is the Spirit who testifies, because the Spirit is the truth. 7For there are three who testify: 8the Spirit, the water, and the blood; and the three agree as one. 9If we receive the witness of men, the witness of God is greater; for this is God’s testimony which he has testified concerning his Son. 10He who believes in the Son of God has the testimony in himself. He who doesn’t believe God has made him a liar, because he has not believed in the testimony that God has given concerning his Son. 11The testimony is this: that God gave to us eternal life, and this life is in his Son. 12He who has the Son has the life. He who doesn’t have God’s Son doesn’t have the life.
13These things I have written to you who believe in the name of the Son of God, that you may know that you have eternal life, and that you may continue to believe in the name of the Son of God.
14This is the boldness which we have toward him, that if we ask anything according to his will, he listens to us. 15And if we know that he listens to us, whatever we ask, we know that we have the petitions which we have asked of him.
16If anyone sees his brother sinning a sin not leading to death, he shall ask, and God will give him life for those who sin not leading to death. There is sin leading to death. I don’t say that he should make a request concerning this. 17All unrighteousness is sin, and there is sin not leading to death.
18We know that whoever is born of God doesn’t sin, but he who was born of God keeps himself, and the evil one doesn’t touch him. 19We know that we are of God, and the whole world lies in the power of the evil one. 20We know that the Son of God has come and has given us an understanding, that we know him who is true; and we are in him who is true, in his Son Jesus Christ. This is the true God and eternal life.
21Little children, keep yourselves from idols.
While first John does not name its author, very early in Church history the apostolic fathers, including Polycarp—who studied under John, assigned this epistle to John the Apostle. Ignatius of Antioch also claimed John authored this letter. Interestingly, Irenaeus wrote that John resided in Ephesus. This is important since the Book of Revelation addresses the churches of Asia. Hence, it is quite probable that the three epistles of John are addressing the same believers in Ephesus.
Moreover, we know that the “beloved disciple” implies John. Equally important is the fact that the author claims to have been an eyewitness of Christ (1:1-4), including claiming to have “touched” him—the “Word of Life”. Thus, to assign this epistle to the second century ignores the eyewitness testimony of the writers of the Gospels. In addition (and equally as important), this epistle was quoted widely in the second century, which implies that it was written long before. In comparing the style and vocabulary in 1, 2, 3, John with the Gospel of John, we observe striking similarities. Thus, if we establish that John penned his gospel, then based on the literary evidence, we can be reasonably certain that the epistles are his as well.
As for the dating of this epistle, we know that early second century believers quoted from it. Thus, to give it a first century date is reasonable. Furthermore, the strand of Gnosticism that John responded to is much more developed than what we observe in the epistles, for example, of Peter and Paul. These apostles refuted a primitive and embryonic kind of Gnosticism, while John was refuting a more established and intellectually rigorous heresy. Given that John died before the close of the first century and the fact that Gnosticism flourished in the mid-second century and onward, we date this letter in the last part of the first century around A.D. 96. While some date this book before the destruction of Jerusalem in A.D. 70, such an early date does not work because the heretical ideas that John is countering would not have had enough time to develop into the more mature synthesis of Greek dualism and Eastern mysticism.
We mentioned earlier that prior to his death John lived and ministered to the saints in Ephesus. In addition to this epistle having the tone of an older man by its frequent habit of referring to its recipients as “little children”, we can assign this letter a later date on other grounds. For example, Paul visited Ephesus multiple times between A.D. 53 and 56. Then, in A.D. 63, Timothy visited Ephesus with Paul as well. In fact, Timothy was still in Ephesus when Paul wrote him some three or four years later (ca. A.D. 67). John, having recognized the threat of Gnosticism and its infiltration by false teachers, sought to set the record straight. John appears to be writing without collaboration against a more virulent Gnostic form. As we read in Genesis, man was created in God’s image, and along with all matter was declared “very good.” The Gnostics turned this idea on its head, and claimed that all created “matter,” including man’s flesh, was evil, or at least created at the lowest level of existence. John deemed this false dualism between man and the created order and God to be heretical. We see Paul in his first epistle to the church at Corinth addressing a primitive yet similar version of Gnosticism that possessed a very low view of matter or the flesh. Thus, it is no wonder that we see a stronger and more fully developed Christology in his first epistle. John's message in 1 John is fourfold: he wanted the joy of his readers to be "complete" (1:4), he admonished them to avoid sin but also to ask forgiveness if they did sin (1:9, 2:1), he wanted them to be able to refute false teachers (2:26), and he wanted them to know or be assured that they "have eternal life" (5:13).
John fought against the Gnostic heresy on two fronts in 1 John by emphasizing the two natures of Jesus Christ – his true humanity and his true deity (centuries later this theology of the union of the two natures would be called the “hypostatic union”). He says he heard, saw and even touched Jesus, confirming the actuality of His humanity. He pulled no punches, saying "Every spirit that confesses that Jesus Christ has come in the flesh is of God, and every spirit that does not confess that Jesus Christ has come in the flesh is not of God" (4:2-3). In fact, he said that those who deny the humanity of Jesus is "the spirit of the Antichrist" (4:3). He also confirms the deity of Jesus, calling Him "the true God and eternal life" (5:20), and affirming Him as one of the Three in the divine unity (5:7).
Finally, in addition to refuting Gnosticism, John also assures the believer of eternal assurance of salvation in Christ. While some maintain that John is stating the opposite, in reading 1 John in its plain reading, and by following the historical-grammatical interpretive method, the message of the assurance of one’s salvation is clear.