"Justified in the name of the Lord Jesus Christ and in the Spirit of our God," "sanctified . . . (and) called to be saints," Christians have become the temple of the Holy Spirit. This "Spirit of the Son" teaches them to pray to the Father and, having become their life, prompts them to act so as to bear "the fruit of the Spirit" by charity in action. Healing the wounds of sin, the Holy Spirit renews us interiorly through a spiritual transformation. He enlightens and strengthens us to live as "children of light" through "all that is good and right and true."
Source: Catechism of the Catholic Church (Vatican.va)