When God touches man's heart through the illumination of the Holy Spirit, man himself is not inactive while receiving that inspiration, since he could reject it; and yet, without God's grace, he cannot by his own free will move himself toward justice in God's sight. 42
Catechism number 1994
Justification is the most excellent work of God's love made manifest in Christ Jesus and granted by the Holy Spirit. It is the opinion of St. Augustine that "the justification of the wicked is a greater work than the creation of heaven and earth," because "heaven and earth will pass away but the salvation and justification of the elect . . . will not pass away."43 He holds also that the justification of sinners surpasses the creation of the angels in justice, in that it bears witness to a greater mercy.