Paul wrote this letter to encourage new believers in their faith, to give them assurance about the eternal state of believers who had died, to remind them of "the coming of the Lord" (4:15), and to exhort them to godly living. He urged them to be at peace, and to "give thanks in all circumstances" (5:18). Thessalonica (present-day Thessaloniki, Greece) was the capital of Roman Macedonia. It was on important trade routes. Paul, twice identified as the author (1:1; 2:18), visited Thessalonica on his second missionary journey but was forced to flee because of Jewish opposition. He sent Timothy to work with the largely Gentile church there, and Timothy brought him good news of their faith (3:6). This is one of Paul's first letters, probably written in a.d. 51.