Thessalonica (modern Salonica) lies near the ancient site of Therma on the Thermaic Gulf at the northern reaches of the Aegean Sea. This city became the capital of Macedonia (ca. 168 B.C.) and enjoyed the status of a “free city” which was ruled by its own citizenry (Acts 17:6) under the Roman Empire. Because it was located on the main east-west highway, Via Egnatia, Thessalonica served as the hub of political and commercial activity in Macedonia, and became known as “the mother of all Macedonia.” The population in Paul’s day reached 200,000 people.
Paul had originally traveled 100 mi. from Philippi via Amphipolis and Apollonia to Thessalonica on his second missionary journey (A.D. 50; Acts 16:1–18:22). As his custom was upon arrival, he sought out the synagogue in which to teach the local Jews the gospel (Acts 17:1,2). On that occasion, he dialogued with them from the OT concerning Christ’s death and resurrection in order to prove that Jesus of Nazareth was truly the promised Messiah (Acts 17:2,3). Some Jews believed and soon after, Hellenistic proselytes and some wealthy women of the community also were converted (Acts 17:4). Mentioned among these new believers were Jason (Acts 17:5), Gaius (Acts 19:29), Aristarchus (Acts 20:4), and Segundus (Acts 20:4).
Because of their effective ministry, the Jews had Paul’s team evicted from the city (Acts 17:5–9), so they went south to evangelize Berea (Acts 17:10). There Paul had a similar experience to Thessalonica with conversions followed by hostility, so the believers sent Paul away. He headed for Athens, while Silvanus and Timothy remained in Berea (Acts 17:11–14). They rejoined Paul in Athens (cf. Acts 17:15,16 with 3:1), from which Timothy was later dispatched back to Thessalonica (3:2). Apparently, Silas afterwards traveled from Athens to Philippi while Paul journeyed on alone to Corinth (Acts 18:1). It was after Timothy and Silvanus rejoined Paul in Corinth (Acts 18:5), that he wrote 1 Thessalonians in response to Timothy’s good report of the church.