‘Salute one another with a holy kiss. All the saints salute you.'
That they salute with a ‘holy kiss' (and thus not sexually oriented) occurs regularly (see Romans 16:16; 1 Corinthians 16:20; 1 Thessalonians 5:26; 1 Peter 5:14). It might be on the cheek, forehead, or regularly on the hand. Its purpose was as a kiss sealing true spiritual love and friendship, and marking them off as God's, for he then speaks of ‘all the saints' saluting them as well. It is thus a symbol of the whole unity of God's people. They are to see themselves as one with all God's people (even if ‘all the saints' means all in Macedonia).