The Lord of Peace, Paul’s Hand, and the Grace of Jesus
Paul asks “the Lord of peace himself” to give the church peace always and in every way. The title strongly fits Jesus in the closing context, which ends with “the grace of our Lord Jesus Christ.”
Verse 17 becomes concrete: Paul says he writes the greeting with his own hand as the distinguishing mark in his letters. Ancient letters were commonly dictated to a secretary, so an autograph ending does not mean Paul personally penned every line. Here it also answers the earlier warning about a message or letter falsely represented as apostolic.