Charity
The practice of the moral life animated by charity gives to the Christian the spiritual freedom of the children of God. He no longer stands before God as a slave, in servile fear, or as a mercenary looking for wages, but as a son responding to the love of him who "first loved us":
If we turn away from evil out of fear of punishment, we are in the position of slaves. If we pursue the enticement of wages, . . . We resemble mercenaries. Finally if we obey for the sake of the good itself and out of love for him who commands . . . We are in the position of children.
Source: Catechism of the Catholic Church (Vatican.va)