Paul, Silvanus, and Timothy, to the assembly of the Thessalonians in God our Father, and the Lord Jesus Christ:
in God our Father: In the first epistle of the Thessalonians, God is designated as "the Father"; here He is designated as "our Father." He is at times called "Father" in relation to Jesus (Romans 15:6; 2 Corinthians 1:3; 2 Corinthians 11:31), and at times He is designated "Father" in relation to His people (Romans 1:7; 1 Corinthians1:3; 2 Corinthians 1:2). It is in the latter sense that the term is used here; the use of "our" emphasizes Paul and the readers have a common Father and are united in a common family.