Paul, Silvanus, and Timothy, to the assembly of the Thessalonians in God the Father and the Lord Jesus Christ: Grace to you and peace from God our Father and the Lord Jesus Christ.
and the Lord: "Jesus" is joined with "God" in such a way as to suggest equality. The three words by which He is identified here are used elsewhere in various orders and combinations. They are employed together here to emphasize the greatness of man’s redeemer. "Lord" emphasizes the master/servant relationship. It tells us that He has the right to command, and we have the responsibility to obey. "Why call ye me Lord, Lord and do not the things which I command you?" (Luke 6:46). This word occurs in every New Testament book with the exception of Titus and the Epistles of John. Its various shades of meaning are summarized by Barclay as follows: