1 Thessalonians 5:26

Salute all the brethren with a holy kiss. [In the East, a kiss was and still is a common salutation among kindred and near friends. Paul did not, by this command, create a church ordinance or ceremony; nor did he even create a new custom. He merely injected a spiritual virtue into an old-established, time-honored custom. This custom never prevailed among the nations of the West, and we feel that we obey Paul when we shake hands with holiness; i. e., with cordial sincerity and honest good-will. The Bible was not written as a work on etiquette, nor was it intended in this case that the Syrian and Grecian custom should become universal.]