I Thessalonians 5:26

Hence it appears this Epistle was first handed to the elders, who communicated it to "the brethren." holy kiss--pure and chaste. "A kiss of charity" (Pe1 5:14). A token of Christian fellowship in those days (compare Luk 7:45; Act 20:37), as it is a common mode of salutation in many countries. The custom hence arose in the early Church of passing the kiss through the congregation at the holy communion [JUSTIN MARTYR, Apology, 1.65; Apostolic Constitutions, 2.57], the men kissing the men, and the women the women, in the Lord. So in the Syrian Church each takes his neighbor's right hand and gives the salutation, "Peace."

The apostle, having spoken in the end of the foregoing chapter concerning the resurrection, and the second coming of Christ, proceeds to speak concerning the uselessness of enquiring after the particular time of Christ's coming, which would be sudden and terrible to the wicked, but comfortable to the saints (Th1 5:1-5). He then exhorts them to the duties of watchfulness, sobriety, and the exercise of faith, love, and hope, as being suitable to their state (Th1 5:6-10). In the next words he exhorts them to several duties they owed to others, or to one another (Th1 5:11-15), afterwards to several other Christian duties of great importance (Th1 5:16-22), and then concludes this epistle (Th1 5:23-28).

5:26 a sacred kiss (see also Rom 16:16; 1 Cor 16:20; 2 Cor 13:12; 1 Pet 5:14): Kissing on the cheek or forehead was a common form of greeting that reflected such sentiments as honor, friendship, and love among family members (Mark 14:44-45; Luke 7:36-47; 15:20; Acts 20:37).