1 Corinthians 1:25
In the meanwhile hold fast the things which have been said, and be ye fellow-helpers with me in the battle; by your way of life attracting them to us and changing them. For, as I am always saying, He that teaches high morality (περὶ φιλοσοφίας) ought first to teach it in his own person, and be such as his hearers cannot do without. Let us therefore become such, and make the Greeks feel kindly towards us. And this will come to pass if we make up our minds not only not to do ill, but also to suffer ill. Do we not see when little children being borne in their father's arms give him that carries them blows on the cheek, how sweetly the father lets the boy have his fill of wrath, and when he sees that he has spent his passion, how his countenance brightens up? In like manner let us also act; and as fathers with children, so let us discourse with the Greeks. For all the Greeks are children. And this, some of their own writers have said, that “that people are children always, and no Greek is an old man.” Now children cannot bear to take thought for any thing useful; so also the Greeks would be for ever at play; and they lie on the ground, grovelling in posture and in affections. Moreover, children oftentimes, when we are discoursing about important things, give no heed to anything that is said, but will even be laughing all the time: such also are the Greeks. When we discourse of the Kingdom, they laugh. And as spittle dropping in abundance from an infant's mouth, which oftentimes spoils its meat and drink, such also are the words flowing from the mouth of the Greeks, vain and unclean. Even if you are giving children their necessary food, they keep on vexing those who furnish it with evil speech, and we must bear with them all the while. (διαβαστάζεσθαι). Again, children, when they see a robber entering and taking away the furniture, far from resisting, even smile on the designing fellow; but should you take away the little basket or the rattle (σεῖστρα) or any other of their playthings, they take it to heart and fret, tear themselves, and stamp on the floor; just so do the Greeks also: when they behold the devil pilfering all their patrimony, and even the things which support their life, they laugh, and run to him as to a friend: but should any one take away any possession, be it wealth or any childish thing whatsoever of that kind, they cry, they tear themselves. And as children expose their limbs unconsciously and blush not for shame; so the Greeks, wallowing in whoredoms and adulteries, and laying bare the laws of nature, and introducing unlawful intercourses, are not abashed.
You have given me vehement applause and acclamation, but with all your applause have a care lest you be among those of whom these things are said. Wherefore I beseech you all to become men: since, so long as we are children, how shall we teach them manliness? How shall we restrain them from childish folly? Let us, therefore, become men; that we may arrive at the measure of the stature which has been marked out for us by Christ, and may obtain the good things to come: through the grace and loving-kindness, etc. etc.
Source: Homilies on First Corinthians (New Advent)