1 Corinthians 5:7-8
10 But why does he call it “old?” Either because our former life was of this sort, or because that which is old is “ready to vanish away,” and is unsavory and foul; which is the nature of sin. For He neither simply finds fault with the old, nor simply praises the new, but with reference to the subject matter. And thus elsewhere He says, “New wine is as a new friend: but if it become old, then with pleasure shall you drink it:” in the case of friendship bestowing his praise rather upon the old than the new. And again, “The Ancient of days sat,” here again, taking the term “ancient” as among those laudatory expressions which confer highest glory. Elsewhere the Scripture takes the term “old” in the sense of blame; for seeing that the things are of various aspect as being composed of many parts, it uses the same words both in a good and an evil import, not according to the same shade of meaning. Of which you may see an instance in the blame cast elsewhere on the old: “They waxed old, and they halted from their paths.” And again, “I have become old in the midst of all mine enemies.” And again, “O you that are become old in evil days.” So also the “Leaven” is often taken for the kingdom of Heaven, although here found fault with. But in that place it is used with one aspect, and in this with another.
11. But I have a strong conviction that the saying about the leaven refers also to the priests who suffer a vast deal of the old leaven to be within, not purging out from their borders, that is, out of the Church, the covetous, the extortioners, and whatsoever would exclude from the kingdom of Heaven. For surely covetousness is an “old leaven;” and whenever it lights and into whatsoever house it enters, makes it unclean: and though you may gain but little by your injustice, it leavens the whole of your substance. Wherefore not seldom the dishonest gain being little, has cast out the stock honestly laid up however abundant. For nothing is more rotten than covetousness. You may fasten up that man's closet with key, and door, and bolt: you do all in vain, while you shut up within covetousness, the worst of robbers, and able to carry off all.
“But what,” say you, “if there are many covetous who do not experience this?” In the first place, they will experience it, though their experience come not immediately. And should they now escape, then fear it the more: for they are reserved for greater punishment. Add to this, that in the event of themselves escaping, yet those who inherit their wealth will have the same to endure. “But how can this be just,” you will say? It is quite just. For he that has succeeded to an inheritance; full of injustice, though he have committed no rapine himself, detains nevertheless the property of others; and is perfectly aware of this; and it is fair he should suffer for it. For if this or that person had robbed and you received a thing, and then the owner came and demanded it back; would it avail you in defence to say that you had not seized it? By no means. For what would be your plea when accused! Tell me. That it was another who seized it? Well: but you are keeping possession. That it was he who robbed? But you are enjoying it. Why these rules even the laws of the heathen recognise, which acquitting those who have seized and stolen, bid you demand satisfaction from those persons in whose possession you happen to find your things all laid up.
If then you know who are the injured, restore and do what Zacchæus did, with much increase. But if you know not, I offer you another way yet; I do not preclude you from the remedy. Distribute all these things to the poor: and thus you will mitigate the evil.
But if some have transmitted these things even to children and descendants, still in retribution they have suffered other disasters.
12. And why speak I of things in this present life? In that day at any rate will none of these things be said, when both appear naked, both the spoiled and the spoilers. Or rather not alike naked. Of riches indeed both will be equally stripped; but the one will be full of the charges to which they gave occasion. What then shall we do on that day, when before the dread tribunal he that has been evil entreated and lost his all is brought forward into the midst, and you have no one to speak a word for you? What will you say to the Judge? Now indeed you may be able even to corrupt the judgment, being but of men; but in that court and at that time, it will be no longer so: no, nor yet now will you be able. For even at this moment that tribunal is present: since God both sees our doings and is near unto the injured, though not invoked: it being certain that whoever suffers wrong, however in himself unworthy to obtain any redress, yet nevertheless seeing that what is done pleases not God, he has most assuredly one to avenge him.
“How then,” you will say, “is such an one well off, who is wicked?” Nay, it will not be so unto the end. Hear what says the Prophet; “Fret not yourself because of the evil doers, because as grass they shall quickly wither away.” For where, tell me, where is he who wrought rapine, after his departure hence? Where are his bright hopes! Where his august name? Are they not all passed and gone? Is it not a dream and a shadow, all that was his? And this you must expect in the case of every such person, both in his own person while living, and in that of him who shall come after him. But not such is the state of the saints, nor will it be possible for you to say the same things in their case also, that it is shadow and a dream and a tale, what belongs to them.
13. And if you please, he who spoke these things, the tent-maker, the Cilician, the man whose very parentage is unknown, let him be the example we produce. You will say, “How is it possible to become such as he was?” Do you then thoroughly desire it? Are you thoroughly anxious to become such? “Yes,” you will say. Well then, go the same way as he went and they that were with him. Now what way went he? One says, “In hunger, and thirst, and nakedness.” Another, “Silver and gold I have none.” Thus they “had nothing and yet possessed all things.” What can be nobler than this saying? What more blessed or more abundant in riches? Others indeed pride themselves on the contrary things, saying, “I have this or that number of talents of gold, and acres of land without end, and houses, and slaves;” but this man on his being naked of all things; and he shrinks not from poverty, (which is the feeling of the unwise,) nor hides his face, but he even wears it as an ornament.
Where now be the rich men, they who count up their interest simple and compound, they who take from all men and are never satisfied? Have ye heard the voice of Peter, that voice which sets forth poverty as the mother of wealth? That voice which has nothing, yet is wealthier than those who wear diadems? For this is that voice, which having nothing, raised the dead, and set upright the lame, and drove away devils, and bestowed such gracious gifts, as those who are clad in the purple robe and lead the mighty and terrible legions never were able to bestow. This is the voice of those who are now removed into heaven, of those who have attained unto that height.
Source: Homilies on First Corinthians (New Advent)