Paul and Barnabas parted ways on account of a dispute involving young Mark, the cousin of Barnabas. Thereafter Paul chose Silas or Silvanus as his partner in spreading the evangel and, upon his return to cities in what is now modern Turkey, selected young Timothy as an assistant. (Acts 15:36-40; 16:1-3) In about 50 CE, Paul, Silvanus, and Timothy brought the glad tidings about Jesus Christ to Thessalonica, the main seaport in Macedonia.
As was his custom, Paul, on the sabbath, went to the synagogue and seized the opportunity to speak to those assembled, using the Scriptures to identify Jesus as the promised Messiah. Some of the Jews responded in faith, as did numerous God-fearing Greeks and certain prominent women who assembled with the Jews at the synagogue. The unbelieving Jews, however, began to oppose Paul and Silas and enlisted some worthless men loitering in the marketplace to form a mob and stir up the populace against them. Thinking that Paul and Silas would be at Jason’s home, the mob went there with the intent of seizing them and bringing them before an assembly of the people. Not finding Paul and Silas, they dragged Jason and a number of other believers before the city officials, making false accusations and stirring up the crowd against Paul and Silas. To be released, Jason and the others were required to make a surety payment. Possibly another condition of their release was that Paul and Silas were to leave Thessalonica, for the believers immediately sent them away during the night to Beroea. Under the cover of darkness, Paul and Silas would have been far safer from possible mob attack than during a departure in daylight. Later, the unbelieving Jews from Thessalonica, upon receiving news of Paul’s activity in Beroea, followed and succeeded in stirring up the populace against him. (Acts 17:1-14)
Note: For pictures of Thessalonica and comments about the city, see bibleplaces.com/thessalonica.htm.