In the year 50, Paul arrived in Thessalonica, a major city and the capital of the province of Macedonia (see Acts 17:1). Here, after being rejected by the Jews, he addressed his preaching to the pagans and succeeded in forming a community. After barely three months, a riot caused by the Jews forced him to leave.
What is going to happen to these recent converts to whom Paul taught the mere basics of Christian life?
Paul is quite concerned, so he sends Timothy to see them and to strengthen their church. Timothy comes back with an optimistic report and Paul, reassured, sends this letter at the beginning of 51.