19 What then? When Nabuchodonosor, after having done such deeds, had made confession, did God give him pardon and the kingdom, and when you repent shall He not give you the remission of sins, and the kingdom of heaven, if you live a worthy life? The Lord is loving unto man, and swift to pardon, but slow to punish. Let no man therefore despair of his own salvation. Peter, the chiefest and foremost of the Apostles, denied the Lord thrice before a little maid: but he repented himself, and wept bitterly. Now weeping shows the repentance of the heart: and therefore he not only received forgiveness for his denial, but also held his Apostolic dignity unforfeited.
Source: Catechetical Lectures (New Advent)