First, there is the valuable caution that the outside does not always match the inside. People can seem happy but be eaten up inside. This is what Nehemiah experienced (read his book) and what many of us deal with in hiding emotional pain. Be careful assuming that everyone with a smile is truly happy inside.
Second, there is the warning that your joy may end. Grief follows, so chasing happy moments cannot be our primary pursuit.
Third, there is the wider application that I hinted at above. When we encounter someone with deep-seated heart pain, it’s very tempting to assume they should just get over it. When we experience it ourselves, we often compound the problem by assuming we should just get over it.
Yet the happiness on the surface has a great deal of difficulty fighting all the way down into the inside. It is far more complex than we give it credit for, and our modern tendency for platitudes over depth does not help.
It is important that we learn to fix our hearts on God and not our feelings. This is why some of the most dangerous advice in the world is to “follow your heart,” for your heart cannot even be trusted to match your face. Your heart may lead you astray if you let it roam undirected.
Fill your heart with the things of God, and then follow it when it is right on those. Otherwise, you won’t know if you are rightly laughing or hiding pain too deep to share.