Thessalonica (Saloniki) was originally called Therme, but was refounded by Cassander c. 315 BC and named Thessalonica after his wife, a step-sister of Alexander the Great. Alike in Macedonian and Roman times it was an important city. The Romans made it the capital of the province of Macedonia in 164 BC and a free city after the battle of Philippi in 42 BC. Through it ran the great Egnatian Road, on its way from Neapolis on the Aegean to Dyrrhachium on the Adriatic. — Guthrie, page 1154.
Paul visited Thessalonica on his second missionary journey. Originally, he had intended to minister throughout Asia (in the area that is now Turkey), but the Holy Spirit prevented him and sent him a vision of a man from Macedonia (now Greece) to come there instead (Acts 16:6-10). Paul first visited Philippi and then Thessalonica.
Now when they had passed through Amphipolis and Apollonia, they came to Thessalonica, where there was a synagogue of the Jews. Then Paul, as his custom was, went in to them, and for three Sabbaths reasoned with them from the Scriptures, explaining and demonstrating that the Christ had to suffer and rise again from the dead, and saying, “This Jesus whom I preach to you is the Christ.” And some of them were persuaded; and a great multitude of the devout Greeks, and not a few of the leading women, joined Paul and Silas. But the Jews who were not persuaded, becoming envious, took some of the evil men from the marketplace, and gathering a mob, set all the city in an uproar and attacked the house of Jason, and sought to bring them out to the people. But when they did not find them, they dragged Jason and some brethren to the rulers of the city, crying out, “These who have turned the world upside down have come here too. Jason has harbored them, and these are all acting contrary to the decrees of Caesar, saying there is another king — Jesus.” And they troubled the crowd and the rulers of the city when they heard these things. So when they had taken security from Jason and the rest, they let them go. Then the brethren immediately sent Paul and Silas away by night to Berea. When they arrived, they went into the synagogue of the Jews (Acts 17:1-10).
Luke, in the passage in Acts, states that Paul preached in the synagogue for three Sabbaths. That does not necessarily mean that he only ministered in the city for three weeks. It may have been that, after three weeks, the opposition of the Jews prevented him from going there and so he began teaching in the house of Jason, who was a Gentile. We have no way of knowing how long he was there, but a few verses make it seem like it was longer than three weeks (Philippians 4:16; 1 Thessalonians 2:9; 2 Thessalonians 3:8).
Unlike the “many” Jews who believed at Berea, only “some” among the Thessalonian Jews believed — and again, in contrast to “some” of the Jews who believed, we read the words: “and of the devout Greeks a great multitude, and of the chief [i.e., distinguished] women, not a few (Acts 17:4).
The “devout Greeks” referred to here, were not merely devout in their own religions, for they were found in the synagogue. Rather, while not proselytes, they were God-fearing Gentiles. This being so, however, it must follow that almost immediately they, with Paul and Silas, went about winning multitudes of pagans to Christ, for not only is it clear that the church at Thessalonica was overwhelmingly a Gentile congregation when Paul wrote, but also that their number was made up overwhelmingly of those who had “turned to God from idols,” not from Judaism (1 Thessalonians 1:8-9). This is further confirmed by the fact that there is not even one quotation from the Old Testament to be found in the letters to the Thessalonians. — Stam, page xii.
From Thessalonica, Paul went to Berea, then to Athens. Paul was worried about the new believers at Thessalonica, so he sent Timothy to visit them (1 Thessalonians 3:1-3), encourage them and report back to Paul. Paul himself went from Athens to Corinth, where he stayed for a year and a half (Acts 18:11) and where he wrote this letter (and 2 Thessalonians) in response to Timothy’s report.
It is generally considered one of Paul’s first letters probably written around A.D. 51.
Timothy told Paul that the new Christians in Thessalonica were standing strong for their faith, but they had some questions, particularly in regard to some members of the church who had died.
The resources I am using for this study are:
The New Bible Commentary, by D. Guthrie and J.A. Motyer — William B. Eerdmans Publishing Company, 1970
The Ryrie Study Bible (NKJV), by Charles Caldwell Ryrie — Moody Press, 1985
The New Scofield Reference Bible, by C.I. Scofield (1909) Oxford University Press, New York
Commentary on the Epistles of Paul to the Thessalonians, by Cornelius R. Stam (1984) Berean Bible Society, Germantown, Wisconsin
Thessalonians, by W.E. Vine and C.F. Hogg (1911) Thomas Nelson Publishers, Nashville, Tennessee
Complete Bible Commentary, by George Williams
When I quote from one of these books, I will use the author’s name and the page number(s).