Paul ends with a prayer, a charge, and a benediction, all wrapped into one profound ending to an eternal message. Paul wrote this letter through the inspiration of the Holy Spirit, so this isn’t just Paul’s personal ending; this is the Word of God for all generations, including those of us who read it today. What this ending provides is an outline for the Christian life till Christ returns.
To begin, Paul never said we would always be happy, but he did say we should always rejoice. How do we reconcile these two things? It begins with understanding the words Paul used in verse 16. The word “rejoice” does not mean the same thing as the word “happy.” Happiness is often predicated upon what "happens" to us, while rejoicing, as Paul used the word here, refers to Christ in us, the hope of glory (Co 1:27).
