Whenever mention is made of religion, the first thing that comes to people's mind is an institution, a society of people dedicated to God. Actually, religion is first and foremost a moral virtue that inclines man to offer God the worship that is His due as the Supreme Being, Creator and Lord of the universe.
The word "religion' is only secondary applied to an institution: people who worship God gather together in society by God's will for the purpose of helping one another honor God properly. It was Christ Himself who founded the Church as a society of religious people to guide and nourish their exercise of the virtue of religion.
Religion is called a "potential part of" or "virtue annexed to" the virtue of justice. Why? Because the paying of a debt is involved. Yet it is not justice because we can never repay God adequately for all that He does for us in creating us, providing for us, redeeming us. Such an infinite debt implies for us a condition of dependency, submission, or the awareness of our being a creature. Because of our debt to the God of all blessings as well as our radical inability to repay it, we stand with profound respect, reverence, indeed awe, before God's sacred transcendence.
Though our debt exceeds our ability to repay, it is precisely here that Jesus Christ comes to our rescue. He is the sole mediator between God and man, the high priest of our religion (see Heb. 4:14; 10-22). The expressions of our virtue of religion have value and are pleasing before God only when offered to God through Christ's virtue of religion. Indeed, the filial devotion proper to the virtue of religion finds its perfection only in Him. Hence, all our prayer and devotion must be joined to His prayer and sacrifice to be acceptable to the Father. Saint Peter urges us: "Draw near to Him, a living stone, rejected by men but chosen and precious to God. Be yourselves as living stones built upon Him into a spiritual house, a holy priesthood, to offer spiritual sacrifice acceptable to the Father through Jesus Christ" (1Pt. 2:3-5).
Yes, as in the case of the other moral virtues, our virtue of religion receives an infinite lift through the infused virtue of religion which enables us to associate ourselves and our whole life to Christ's prayer and sacrifice. This alone empowers us to make of our life one long, persevering act of self-offering wholly pleasing to God.
The principal act of the virtue of religion is devotion. This is not simply a matter of feeling devout. Rather it means a consecration of our person to God in absolute and total submission. Saint Thomas thoughtfully defines devotion as a promptness of the will for whatever concerns the worship of God. It is the eager and complete homage of our will, and as such it is the generator of all further acts of worship. If the inner man is without reserve given over to God, all other religious acts follow, not only logically, but with depth of meaning. Failing this genuine interior devotion of the will, worship of God is meaningless.
In sum, Saint Augustine said: "The perfection of religion is to imitate Him whom we adore."
Source: Father John H. Miller
#2105 The duty of offering God genuine worship concerns man both individually and socially. This is "the traditional Catholic teaching on the moral duty of the individuals and societies toward the true religion and the one Church of Christ." (Catechism of the Catholic Church.)