1The elder, to the chosen lady and her children, whom I love in truth, and not I only, but also all those who know the truth, 2for the truth’s sake, which remains in us, and it will be with us forever: 3Grace, mercy, and peace will be with us, from God the Father and from the Lord Jesus Christ, the Son of the Father, in truth and love.
4I rejoice greatly that I have found some of your children walking in truth, even as we have been commanded by the Father. 5Now I beg you, dear lady, not as though I wrote to you a new commandment, but that which we had from the beginning, that we love one another. 6This is love, that we should walk according to his commandments. This is the commandment, even as you heard from the beginning, that you should walk in it.
7For many deceivers have gone out into the world, those who don’t confess that Jesus Christ came in the flesh. This is the deceiver and the Antichrist. 8Watch yourselves, that we don’t lose the things which we have accomplished, but that we receive a full reward. 9Whoever transgresses and doesn’t remain in the teaching of Christ doesn’t have God. He who remains in the teaching has both the Father and the Son. 10If anyone comes to you and doesn’t bring this teaching, don’t receive him into your house, and don’t welcome him, 11for he who welcomes him participates in his evil deeds.
12Having many things to write to you, I don’t want to do so with paper and ink, but I hope to come to you and to speak face to face, that our joy may be made full. 13The children of your chosen sister greet you. Amen.
Beginning this sentence with “for” indicates that John is now explaining the need for walking in God’s truth and obeying His command to love one another. John warns that “many deceivers” were in the world. This is the same warning he gave in his first epistle when warning about the antichrists and future Antichrist (1 John 4:1-6).
The false teachers deny Jesus’ incarnation. This may be an allusion to an early form of Gnosticism. This teaching denied the physical body of Christ while acknowledging His deity. It reflected Greek dualism that viewed the spiritual world as pure and good and the physical world as evil. It concluded from this that, since Jesus is God, He could not have a physical body without being corrupted by it. Thus, Jesus only appeared to have a body.
As in his First Epistle, John identifies this teaching, and so the false teachers, with the Antichrist.