Conscience enables one to assume responsibility for the acts performed. If man commits evil, the just judgment of conscience can remain within him as the witness to the universal truth of the good, at the same time as the evil of his particular choice. The verdict of the judgment of conscience remains a pledge of hope and mercy. In attesting to the fault committed, it calls to mind the forgiveness that must be asked, the good that must still be practiced, and the virtue that must be constantly cultivated with the grace of God:
We shall . . . Reassure our hearts before him whenever our hearts condemn us; for God is greater than our hearts, and he knows everything.
Source: Catechism of the Catholic Church (Vatican.va)