The Second Letter of John is addressed to a Christian community in Asia Minor (now Turkey ). The faith of that community is threatened by the presence of false teachers, who venture “beyond the doctrine of Christ” (verse 9) and “do not confess Jesus Christ manifested in the flesh” (v. 7), that is , deny the mystery of the Incarnation. John wants to alert believers against those teachings. So he reminds them that they possess the knowledge of the truth, and that they must live in the truth, loving one another, according to the command received from the Father and transmitted by the Church from the beginning (vs. 4-6).
The text begins with an initial greeting:
1) I, the Priest – and not only me, but also all who have known the truth – greet the chosen community and its members, whom I truly love, 
2) because of the truth that remains in us and that will be with us forever.
3) The grace, mercy and peace of God the Father and of his Son Jesus Christ will also be with us, in truth and in love. [two]
The commandment of love
4) I have been very happy to find some of your children who live in the truth, according to the commandment we have received from the Father.
5) And now I beg you: let us love one another. With which I do not communicate a new commandment, but the one that we have from the beginning. 
6) Love consists in living according to God’s commandments. And the commandment that you have learned from the beginning is to live in love.
7) Because many seducers have invaded the world who do not confess Jesus Christ manifested in the flesh. They are the Seducer and the Antichrist! 
8) You are alert not to lose the fruit of your works, so that you can receive a perfect retribution.
9) Everyone who ventures beyond the doctrine of Christ and does not remain in it, is not united to God. Instead, he who abides in his doctrine is united to the Father, and also to the Son. 
10) If someone appears before you and does not bring this same doctrine, do not receive him at his house or greet him.
11) Because the one who greets him will become an accomplice of his evil deeds. 
12) I would have many other things to write to you, but I did not want to do it by letter, because I hope to go see you to speak with you personally, so that our joy is complete.
13) The children of this chosen Community also greet you fraternally.