Paul could have sat back and been happy with Timothy’s encouraging report of how the Thessalonians have been growing in their faith and confidence in the Lord. Paul continues to write to them pushing them to go beyond what the Lord has called them to do “now we ask you and urge you in the Lord Jesus to do this more and more.” (vs:1b)
I think Paul understood the position of the Thessalonians well, they were in a place were they may have felt that they were “walking on water”, Paul did not want them to be comfortable in their faith, he wanted them to realize that they could be doing more. The first half of chapter 4 of 1 Thessalonians teaches us that the Thessalonian people were surrounded by the same temptations and evils of sexual immorality we are faced with today. These instructions were not something Paul had come up with on his own; it was by the authority of the Lord Jesus that Paul could present these instructions to them.
Each time I read through this passage I have to think about the fact that Paul was writing these words as a letter to the Thessalonians, I can only imagine the longing Paul had to be with them. Chapter 2:18 Paul writes that “Satan blocked our way”, Paul knew that Satan was keeping them separated so as to discourage and dishearten them, yet Paul continued to encourage and teach through these written words.
Just like Paul and the Thessalonians Satan tosses up similar roadblocks in our lives today, trying to send us in a different direction away from God. Paul’s words are as much alive today as they were back then, our lives and our focus has to be on the Lord. When we accept and live out the instructions of purity and holy living we will be living a life that is pleasing God.
Steve.
steveworkingthroughtheword.com 
Well done Steve, I think that these words apply as much today if not more due to the media explosion and It is really hard to avoid the temptations that we are exposed to all the time.