2 Thus also Paul did; for having said, “He counted me faithful, putting me into the ministry,” he goes on to add, “who was before a blasphemer, a persecutor, and injurious.” “Let the life of the servant,” says he, “be openly exposed, so that the lovingkindness of the Master be apparent. For although I have received the remission of sins, I do not reject the memory of those sins.” And this not only manifested the lovingkindness of the Lord, but made the man himself the more illustrious.
For when you have learned who he was before, then you will be the more astonished at him; and when you see out of what he came to be what he was, then you will commend him the more; and if you have greatly sinned, yet upon being changed you will conceive favourable hopes from this instance. For in addition to what has been said, such an example comforts those who are in despair, and causes them again to stand erect. The same thing also will be the case with regard to our city; for all the events that have happened serve to show your virtue, who by means of repentance have prevailed to ward off such wrath, while at the same time they proclaim the lovingkindness of God, who has removed the cloud that was so threatening, in consequence of a small change of conduct, and so raises up again all those who are sunk in despair, when they learn, from our case, that he who looks upward for the Divine help, is not to be overwhelmed, though innumerable waves should encompass him on all sides.
Source: Homilies on the Statues (New Advent)