11 In this way too did Paul, when he had found the Corinthians puffed up and inflamed, compose them, and make them more considerate. For they were priding themselves on those very things, touching which they ought to have been ashamed, and to have hid their face. But after they had received the letter, hear the change in them, of which the Teacher himself has borne witness for them, saying on this wise: for “this very thing, that you sorrowed after a godly sort, what carefulness it wrought in you, yea, what clearing of yourselves, yea, what indignation, yea, what zeal, yea, what revenge.” In this way do we bring to order servants and children, wives, and friends, and make our enemies friends.
In this way the great men too, they that were dear to God, became better. David, for instance, after his sin, when he had had the benefit of certain words, then it was that he came unto that most excellent repentance; and the apostles also by this mean became what they did become, and drew after them the whole world.
“And what is the profit,” one may say, “when any one hears, but does not what is said?” No little will the profit be even from hearing. For he will go on to condemn himself, and to groan inwardly, and will come in time also to do the things that are spoken of. But he that does not even know that he has sinned, when will he cease from his negligence? When will he condemn himself?
Let us not therefore despise the hearing of the divine Scriptures. For this is of Satan's devising; not suffering us to see the treasure, lest we should gain the riches. Therefore he says that the hearing the divine laws is nothing, lest he should see us from the hearing acquiring the practice also.
Knowing then this his evil art, let us fortify ourselves against him on all sides, that being fenced with this armor, we may both abide unconquered ourselves, and smite him on the head: and thus, having crowned ourselves with the glorious wreaths of victory, we may attain unto the good things to come, by the grace and love towards man of our Lord Jesus Christ, to whom be glory and might for ever and ever. Amen.
Source: Homilies on the Gospel of St. Matthew (New Advent)