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.
Paul’s success with the church there had brought them sever persecution from the Jews. When he was forced to leave them he was very eager to learn how things were going and sent Timothy to them (1 Thessalonians 3:1-5; 1 Thessalonians 2:17). Timothy’s report of their steadfastness in the faith and some of the questions (especially about Jesus’ second coming) may have prompted this letter.