2 Corinthians 2:11
“That no advantage may be gained over us by Satan: for we are not ignorant of his devices.”
Do you see how he both commits the power to them and again takes away that by that he may soften them, by this eradicate their self will. But this is not all that he provides for by this, but shows also that should they be disobedient the harm would reach to all, just as he did at the outset also. For then too he said, “A little leaven leavens the whole lump.” And here again, “Lest Satan should get an advantage of us.” And throughout, he makes this forgiveness the joint act of himself and them. Consider it from the first. “But if any,” says he, “have caused sorrow he has caused sorrow not to me, but in part (that I press not too heavily) to you all.” Then again, “Sufficient to such a one is this punishment which was” inflicted by the “many.” This is his own decision and opinion. He rested not however with this decision, but again makes them partners saying, “So that contrariwise ye should rather forgive” him “and comfort” him. “Wherefore I beseech you to confirm your love towards him.” Having thus again made the whole their act, he passes to his own authority, saying, “For to this end did I write unto you, that I might know the proof of you, whether you are obedient in all things.” Then, again, he makes the favor theirs, saying, “To whom you forgive anything.” Then, his own, “I” forgive “also:” saying, “if I have forgiven anything, it is for your sakes.” Then both theirs and his, “For,” says he, “if I have forgiven any thing, for your sakes forgave I it in the person of Christ,” either [that is] for the glory of Christ, or as though Christ commanding this also, which was most effectual to prevail with them. For after this they would have feared not to grant that which tended to His glory and which He willed. Then again he signifies the common harm should they disobey, when he says, “Lest Satan should get an advantage of us;” well naming it, getting advantage. For he no more takes his own, but violently seizes ours, for he is reformed. And tell me not that this one only becomes the wild beast's prey, but consider this also, that the number of the herd is diminished, and now especially when it might recover what it had lost. “For we are not ignorant of his devices,” That he destroys even under the show of piety. For not only by leading into fornication can he destroy, but even by the contrary, the unmeasured sorrow following on the repentance for it. When then besides his own he takes ours too, when both by bidding to sin, he destroys; and when we bid repent, violently seizes; how is not this case getting “advantage?” For he is not content with striking down by sin, but even by repentance he does this except we be vigilant. Wherefore also with reason did he call it getting advantage, when he even conquers our own weapons. For to take by sin is his proper work; by repentance, however, is no more his; for ours, not his, is that weapon. When then even by this he is able to take, think how disgraceful the defeat, how he will laugh at and run us down as weak and pitiful, if he is to subdue us with our own weapons. For it were matter for exceeding scorn and of the last disgrace, that he should inflict wounds on us through our own remedies. Therefore he said, “for we are not ignorant of his devices,” exposing his versatility, his craftiness, his evil devices, his malice, his capacity to injure under a show of piety.
6. These things then having in mind, let us too never despise any one; nor ever, though we fall into sin, despair; on the other hand, again, let us not be easy-minded afterwards, but, when we transgress, afflict our minds and not merely give vent to words. For I know many who say indeed that they bewail their sins, but do nothing of account. They fast and wear rough garments; but after money are more eager than hucksters, are more the prey of anger than wild beasts, and take more pleasure in detraction than others do in commendations. These things are not repentance, these things are the semblance and shadow only of repentance, not repentance itself. Wherefore in the case of these persons too it is well to say, Take heed “lest Satan should get an advantage of us, for we are not ignorant of his devices;” for some he destroys through sins, others through repentance; but these in yet another way, by suffering them to gain no fruit from repentance. For when he found not how he might destroy them by direct [attack,] he came another road, heightening their toils, while robbing them of the fruits, and persuading them, as if they had successfully accomplished all they had to do, therefore to be neglectful of what remains.
That we may not then fruitlessly afflict ourselves, let us address a few words to women of this character; for to women this disorder especially belongs. Praiseworthy indeed is even that which now ye do, your fasting and lying on the ground and ashes; but except the rest be added, these are of no avail. God has showed how He remits sins. Why then forsaking that path, do ye carve another for yourselves. In old time the Ninevites sinned, and they did the things which you too now are doing. Let us see however what it was that availed them. For as in the case of the sick, physicians apply many remedies; howbeit the man of understanding regards not that the sick person has tried this and that, but what was of service to him; such must be also our inquiry here. What then was it that availed those barbarians? They applied fasting unto the wounds, yea applied extreme fasting, lying on the ground too, putting on of sackcloth, and ashes, and lamentations; they applied also a change of life. Let us then see which of these things made them whole. And whence, says one, shall we know? If we come to the Physician, if we ask Him: for He will not hide it from us, but will even eagerly disclose it. Rather that none may be ignorant, nor need to ask, He has even set down in writing the medicine that restored them. What then is this? “God,” says He, “saw that they turned every one from his evil way, and He repented of the evil that He had said He would do unto them.” He said not, He saw [their] fasting and sackcloth and ashes. And I say not this to overturn fasting, (God forbid!) but to exhort you that with fasting ye do that which is better than fasting, the abstaining from all evil. David also sinned. Let us see then how he too repented. Three days he sat on ashes. But this he did not for the sin's sake, but for the child's, being as yet stupefied with that affliction. But the sin by other means did he wipe away, by humbleness, contrition of heart, compunction of soul, by falling into the like no more, by remembering it always, by bearing thankfully every thing that befalls him, by sparing those that grieve him, by forbearing to requite those who conspire against him; yea, even preventing those who desire to do this. For instance, when Shimei was bespattering him with reproaches without number and the captain who was with him was greatly indignant, he said, “Let him curse me, for the Lord has bidden him:” for he had a contrite and humbled heart, and it was this especially which wiped away his sins. For this is confession, this is repentance. But if while we fast we are proud, we have been not only nothing profited but even injured.
Source: Homilies on Second Corinthians (New Advent)