(God) gave himself to us through his Spirit. By the participation of the Spirit, we become communicants in the divine nature.... For this reason, those in whom the Spirit dwells are divinized. 37
Catechism number 1990
Justification detaches man from sin which contradicts the love of God, and purifies his heart of sin. Justification follows upon God's merciful initiative of offering forgiveness. It reconciles man with God. It frees from the enslavement to sin, and it heals.