4 Having thus, you see, stopped the mouths of those who pass such sentences, he travails next with strong feeling ready to break out and come upon the unclean person. And like as when a storm is coming on, some clouds fraught with darkness run before it; afterwards, when the crash of the thunders arises and works the whole heavens into one black cloud, then all at once the rain bursts down upon the earth: so also did it then happen. For though he might in deep indignation have dealt with the fornicator, he does not so; but with fearful words he first represses the swelling pride of the man, since in truth, what had occurred was a twofold sin, fornication, and, that which is worse than fornication, the not grieving over the sin committed. For not so much does he bewail the sin, as him that committed it and did not as yet repent. Thus, “I shall bewail many of those,” says he, not simply “who have sinned heretofore,” but he adds, “who have not repented of the uncleanness and impurity which they wrought.” For he who after sinning has practised repentance, is a worthy object not of grief but of gratulations, having passed over into the choir of the righteous. For, “declare thou your iniquities first, that you may be justified:” but if after sinning one is void of shame, he is not so much to be pitied for falling as for lying where he is fallen.
Now if it be a grievous fault not to repent after sins; to be puffed up because of sins, what sort of punishment does it deserve? For if he who is elate for his good deeds is unclean, what pardon shall he meet with who has that feeling with regard to his sins?
Since then the fornicator was of this sort, and had rendered his mind so headstrong and unyielding through his sin, he of course begins by casting down his pride. And he neither puts the charge first, for fear of making him hardened, as singled out for accusation before the rest; nor yet later, lest he should suppose that what related to him was but incidental. But, having first excited great alarm in him by his plain speaking towards others, then, and not till then, he goes on to him, in the course of his rebuke to others giving the man's wilfulness a share beforehand.
For these same words, viz. “I know nothing against myself, yet am I not hereby justified,” and this, “He that judges me is the Lord, who will both bring to light the hidden things of darkness, and make manifest the counsels of the hearts,” glance not lightly both upon that person, and upon such as act in concert with him and despise the saints. “For what,” says he, “if any outwardly appear to be virtuous and admirable persons? He, the Judge, is not a discerner of externals only, but also brings to light all secrets.”
Source: Homilies on First Corinthians (New Advent)