The church in Thessalonica was only a couple of years old when Paul wrote this letter. In this part of the letter Paul is instructing the Thessalonians to live to please God. His first instruction for sanctification is to avoid sexual immorality, our biggest weakness. Sexual immorality has caused countries to fall, churches to fall, pastors to fall and families to fall. It is no mistake that Paul starts with this...if we can take control of our own bodies, we are well on our way to pleasing God.