(based on a talk by Prof. Plinio Corrêa de Oliveira)
We must serve God with joy and communicate this joy in doing holy things. St. Thomas Aquinas named this weariness for holy things and the subsequent sadness of living in the service of God, acedia, which means weariness and lack of joy and desire for things.
Today, joy is only seen in the things of the world. People no longer find joy in virtue and serving Our Lord. Along with the saints, we are called by God to communicate this joy, which is not the giddy joy of a gag or a joke. This is the joy without silly jokes, joy without being a clown. It is the joy of seriousness, which is the highest and noblest of all joys.