This formula appears in a similar form in many of Paul’s letters (for example, Rom 16.16; 1 Cor 16.20; 2 Cor 13.12; 1 Thes 5.26) and appears to be a popular formula in the early church. Exegetes say that this reflects the practice of Christians embracing each other in their meetings, either at the end or at the reading of an apostolic letter (compare New American Bible “embrace of true love”). The embrace itself is a sign of their fellowship as brothers and sisters in Christ and therefore of their deep spiritual ties with one another. Christian love is literally “love,” but since in modern culture the kiss has become associated primarily with romantic love, the qualification of love as Christian love is entirely justified (compare Knox “kiss of fellowship”). Most translations retain the expression, but one modern translation probably has gone too far in indicating its modern significance (Phillips “Give each other a handshake all around as a sign of love”). Normally, an expression like “Greet each other fervently as brothers and sisters in Christ” would be sufficient to express the meaning of the expression. One may also use an expression such as “greet one another affectionately as a fellow Christian” or “greet one another in a way that shows your love for one another as believers.”
The letter ends with a sentence benediction. For peace, see 1.2. All of you who belong to Christ is literally “all of you who are in Christ,” for which see note on 3.17. All of them of course belong to Christ, and attention must be paid in the translation so as not to give the impression that some of those being greeted do not belong to him. To call their attention to this fact at the end of the letter is indeed a fitting conclusion, for it reminds them of their new sphere of existence which is found in and defined by their relationship to Christ.
The final benediction May peace be with all of you who belong to Christ must be expressed in some languages as a type of prayer, and thus must be introduced by an expression which identifies it as a prayer, for example, “I pray that all of you who belong to Christ may experience peace.”
Quoted with permission from Arichea, Daniel C. and Nida, Eugene A. A Handbook on The First Letter from Peter. (UBS Handbook Series). New York: UBS, 1980. For this and other handbooks for translators see here .