After speaking of the return of Jesus Christ, and after assuring us that we shall live with Him forever, Paul urged us to do two things:

Therefore comfort each other and edify one another, just as you also are doing (1 Thessalonians 5.11).

Trials and temptations attack us daily and those things discourage us. Therefore we need to remind one another of what is coming, that someday the Lord shall appear unexpectedly, and He shall take us to live with Him in a place where the troubles and tribulations of this life will never be known.