Verses 1-16
Paul's work in Thessalonica (2:1-16)
In Paul's day there were some travelling preachers whose main aim was to make money, usually by crafty or dishonest methods. Certain people in the Thessalonian church, apparently angry that Paul had left them suddenly, accused him of being one of these untrustworthy travelling preachers. They said he was concerned only for himself, not for them. Paul replies that he has never used smooth words to deceive people or gain a following. His readers know that in both Philippi and Thessalonica he was so straightforward in preaching God's message that he suffered bodily harm (2:1-5).
Paul wanted neither praise nor money. As an apostle he had a right to be supported financially by those to whom he ministered, but he did not claim this right. Far from trying to make financial profit from the Thessalonians, he gave freely to help them (6-8). He worked at his trade to earn enough money to support himself, and spent the rest of his time preaching (9). The Christians in Thessalonica know that his conduct among them was without fault. It was a living example of the kind of life that Paul urged them to live, the life that pleases God and brings glory to his name (10-12).
The Thessalonians knew that the gospel they received was not something of human creation but was a message from God himself, and they were prepared to suffer for it. They were persecuted by the citizens of their own country, just as the Christians in Judea were persecuted by the Jews (13-14). Not only had the Jews crucified the Lord Jesus and rejected God themselves, but they were now trying to prevent the message of Jesus from reaching the Gentiles. In doing so they were building up a terrible divine judgment against themselves (15-16).
Verse 17
After leaving Thessalonica (2:17-3:13)
Having reminded the Thessalonians of his work and conduct while among them, Paul now outlines his thoughts and feelings for them since he left. In spite of what his opponents are saying, his failure to return does not mean that he has no interest in them. Several times he has tried to return, but each time something has stopped him (17-18). He wants to have joy, not shame, at Christ's return, and for this reason he is eager to see his converts grow and develop in the faith (19-20).
Paul was faced with a difficulty. He was not able to return to Thessalonica, yet he was not able to rest if he did not return. He therefore did the next best thing and sent his fellow worker Timothy, even though it meant that Paul had to face alone the difficult task of preaching in Athens (3:1-2; cf. Acts 17:16-34). Timothy's task was to strengthen the Thessalonians' faith to withstand persecution. Paul did not want the good work already done among them to be destroyed through people turning away from Christ (3-5).
Timothy has now returned and Paul is overjoyed at the news he has brought. The believers in Thessalonica have progressed in their faith and love, and their longing to see Paul is as great as his longing to see them (6-8). He does not know how to thank God for such good news. He desires more than ever to revisit them, so that he can further help their growing faith (9-10). But he will return only if God wants him to. God is the one who guides their progress, and only he can make them strong. In view of Christ's return they should increase in love and holiness (11-13).