Paul came to Thessalonica on his second journey (A.D. 50-53; Acts 17). Paul describes the reception the Thessalonians gave to the gospel in these words:
For they themselves report about us what kind of a reception we had with you, and how you turned to God from idols to serve a living and true God, and to wait for His Son from heaven, whom He raised from the dead, that is Jesus, who rescues us from the wrath to come. (1 Thessalonians 1:9-10 NAU)
The church of the Thessalonians had many questions about the second coming of Christ. Paul addressed these questions in the two letters he wrote to the church from Corinth.
We know little of individuals associated with the church. Jason seems to be one of the earliest converts in Thessalonica (Acts 17:5-9). Aristarchus, a Macedonian of Thessalonica accompanied Paul on the voyage to Rome (Acts 27:2). He was one of the messengers who went with Paul on the return from the third journey (Acts 20:4). When Demas forsook Paul he went to Thessalonica (2 Timothy 4:10).
The photo below shows ruins of the Roman Forum in Thessaloniki, the second largest city of Greece. This area of the city was destroyed by a fire in 1917. During preparations for constructing new buildings these ruins were discovered. They date to the second and third century A.D. (See Fant and Reddish, A Guide to Biblical Sites in Greece and Turkey, 137). Perhaps there are older ruins below these. Notice how the modern city is built around the ancient ruins on a higher level. Can you imagine what might be underneath all of those buildings?