Paul and Silas visited Thessalonica on Paul’s 2nd missionary trip, spending only about three weeks there… during which some Jews and a greater number of Gentiles were converted and a church was planted (see; Acts 17:1-11). The Second Coming is a major theological issue in both letters. The theme for both letters is the sanctification of the believer, or living in the light of Christ’s 2nd coming.
(* See attached PDF outline)