Paul’s letters to the Thessalonian Christians, along with his letter to the Galatians, comprise the earliest documents of the New Testament.
The Thessalonian letters were written on Paul’s second missionary journey. The second journey was filled with difficulties. Early on, hindrances in Asia Minor dogged their every move. Finally, Paul and his companions crossed the Agean Sea and went to Philippi. A Church was started there, but not without considerable persecution. The group moved to Thessalonica, the capital city of Macedonia, but again found themselves opposed by both Jewish and gentile authorities. The opposition was so extreme that some of the new converts were forced to post a bond, obligating them to financial penalties if unrest arose again in the city. The Christians had no intention of causing trouble, but they could not speak for their opponents who would stop at nothing to persecute the young movement then taking the world by storm. To avoid trouble for the young church in Thessalonica, Paul and his coworker Silas left town under the cover of night for the quieter refuge of a town off the beaten track to the south, Berea.
Luke, in Acts is careful to note that all the persecutions came from people who, for a variety of selfish reasons, opposed the gospel of Christ. But surely it looked to the public as if Paul and his companions were just a group of troublemakers, and the new Christians left behind in those cities would suffer tremendous ridicule. Additionally, would not the new converts wonder why, if these men were truly emissaries of God, they had to endure so much opposition from sinful men?
Paul knew how it looked. And so, not so very long after leaving Thessalonica, Paul wrote the first and then second letter to the Thessalonians. In the first letter, he reminds them that, unlike so many traveling philosophers of his day, Paul, rather than take support from his converts, instead supported them, caring for them as a mother or a father would care for their child (chapters 1 and 2). In chapter 3 he compliments them on their behavior since he left, and in chapters 4-5 he gives this young church direction for living the Christian life.
The first letter is important because it gives us insight to how Paul conducted his ministry, and how Christians should conduct their own today. But also, it is important because Paul reminds his readers of what he taught these new converts when he was with them just a few weeks earlier. As such, it reveals the basic teaching of Christian missionaries and gives us an outline of what every Christian ought to know.