Gaudete in Domino semper: iterum dico, gaudete. Modestia vestra nota sit omnibus hominibus: Dominus enim prope est. Nihil solliciti sitis: sed in omni oratione petitiones vestræ innotescant apud Deum. Benedixisti Domine terram tuam: avertisti captivitatem Jacob.
"Rejoice in the Lord always; again I say, rejoice. Let your forbearance be known to all, for the Lord is near at hand; have no anxiety about anything, but in all things, by prayer and supplication, with thanksgiving, let your requests be known to God. Lord, you have blessed your land; you have turned away the captivity of Jacob." (Philippians 4:4–6; Psalm 85 (84):2).
Below, you will find an amazing audio clip from a Vatican Radio program by Fr. Paul Murray, O.P. of the Irish Dominican Province who speaks about Joy (and Humor!) in the writings of the "Common Doctor of the Church," St. Thomas Aquinas.