First Thessalonians is a great, big thank-you note. Paul is giving God the Father all the glory for preserving the young Macedonian church in the face of affliction. Thessalonica proved to be Timothy’s first great training assignment, as Paul was unable to return to that city. Timothy went in there and reinforced the broad areas of Scripture that Paul had taught when the church was first established.
“To the Thessalonians” is named for the recipients of the epistle.
The Apostle Paul is the primary author, with the scribal assistance and courier services of Silvanus (Silas) and Timothy.