This is perhaps Paul’s most affectionate letter. He writes as a loving, gentle, and caring father, who is seeking to support and nurture the young church in Thessalonica. The central theme of Paul’s letter is to encourage this church (and by extension, all followers of Jesus) to stand firm in their faith in the midst of opposition and to continue to grow towards spiritual maturity, that is to pursue a deeper understanding of God and one’s relationship to him.
In contrast to Paul’s first letter to the church in Thessalonica, which was warm and affectionate, this letter takes a more formal, authoritative tone. It is more theological in nature; it also contains teaching about the return, or “second coming” of Jesus. Not only does Paul encourage the Thessalonian church in this letter, but he also scolds them for not living and acting befitting of followers of Jesus, including the need to guard against false teaching or heresy.