The letters to the Thessalonians were written to address questions of the second coming, laziness, offer encouragement in the face of intense persecution, what happens to those that have died, and the healthy use of spiritual gifts . There were concerns among the faithful that those that have died would not participate in the second coming. The Thessalonians erroneously thought that the dead had zero hope to the second coming. Paul put this fear to rest by “assuring them that the dead would rise first and go and meet the Lord  .” Because of this erroneous thought there were those among them that were mooching off of the wealthy. Paul Told them to work hard to make their own living, and be an example of hard work for those around them.
In 2 Thessalonians Paul again addressed the issue of Christ’s return. There was a false writing attributed to Paul, and Paul said “this is how I write with my own hand .” He was telling the Thessalonians that this false letter was not his and that is was a false teaching. This false teacher spread a doctrine that said that the return of Christ had already occurred, but Paul “assured the Thessalonians that these events had not yet begun, even though someone had used devious methods to suggest that the events were already unfolding  .” He then told the Thessalonians to remain in firm in what he had taught them.
These false doctrines were perpetrated by the opponents of the faith which were the Judaizers, those Christians not pulling their own weight, false writings attributed to him, and the low moral standards in Thessalonica. These things all contributed to Paul having to set things straight with the Thessalonians.
 Lea, Thomas D., and Black. The New Testament: Its Background and Message. 2d ed. Nashville, TN: Broadman and Holman, 2003, 379-380.
 Ibid, 382.
 Carson, D. A., and Douglas J. Moo. An Introduction to the New Testament. 2d ed. Grand Rapids, MI: Zondervan, 2005, 536.
 Lea, Thomas D., and Black. The New Testament: Its Background and Message. 2d ed. Nashville, TN: Broadman and Holman, 2003, 384.