Religion is the good habit of a man to continually praise and worship God, recognizing that he can never give or repay God for all God has done for a man. The habitual acts of the virtue of Religion are carried out consistent with the teachings of the Catholic Church through the sub-virtues (good habits) of Prayer, Devotion (reception of the Sacraments, pious acts, adoration) and various forms of Sacrifice (oaths, tithes, alms, fasts, service, self-offering to God). The man who practices the virtue of Religion keeps a daily routine (or, rule) which integrates his priority on seeking God with his worldly responsibilities and follows recognized devotions of the Church. The virtue of Religion is also often revered to as Piety.

The opposing vices of Religion include the bad habits of False Worship (practicing false religions, superstition, idolatry, simony, witchcraft, devil worship) and Irreligion (rejection of God and the duty to praise, worship and honor Him). The man who practices False Worship or Irreligion lives without the blessings of the Sacraments and without the sure grace of the Holy Spirit in his life to guide and strengthen him, and leaves himself vulnerable to the temptations and attacks of Satan and his demons; False Worship and Irreligion inevitably lead to unhappiness and discontent.