Paul was the author. It was written around 52-54 A.D. The theme is The Great Tribulation and the Second Coming of Jesus Christ. Paul planted the church in Thessalonica during his second missionary journey with Timothy, Silas, and Luke. In Acts 17, Paul was in Thessalonica for three weeks, and taught them for three consecutive Saturdays. He was chased out by unbelievers, yet left a dynamic, young church behind.

Paul travelled to Berea, Athens, and Corinth. Evidently while in Corinth, he received news about how things were transpiring in Thessalonica, including questions by the church concerning some of his teachings. The book of 1 Thessalonians was written to answer their questions and correcting some of their misunderstandings. Soon after sending the first letter, he received news of from them of additional questions and misunderstandings. He wrote 2 Thessalonians to continue clarification of what he taught them earlier.

First Thessalonians focused predominantly on the Rapture of the Church. Second Thessalonians focuses mainly on the Great Tribulation and the Second Coming of Jesus Christ. Some false teachers were teaching that the Great Tribulation was currently active. Paul corrects this error by writing, that, although they were currently suffering persecution and tribulation, it was not the Great Tribulation. This period of time will clearly be distinct by the rise of the AntiChrist, as a world leader, and end when Jesus literally returns to the earth to destroy His enemies. Paul makes the distinction between the Rapture, when and where Jesus comes and takes the Church up into the air to meet Him, and The Second Coming following The Great Tribulation, when Jesus returns with His Church, when He will return to conquer His enemies, subdue the earth, and set up His earthly thousand year reign and kingdom.

Therefore, 1 Thessalonians comforts Christians by telling them the Rapture is literal and is imminent. While 2 Thessalonians comforts us by informing us we are not presently in the the Great Tribulation, and we will never go through the Great Tribulation. This is splendid assurance and hope, especially for any Christian who are suffering.