Hebrews 13:16
This brings us near to God: then we even have God for our debtor. But when we are in prosperity, it is we who are debtors and liable to be called to account. For when we are in prosperity, we are debtors to God: and oftentimes these things bring a judgment upon us, while those are for a payment of sins. Those [afflictions] draw down mercy, they draw down kindness: while these on the other hand lift up even to an insane pride, and lead also to slothfulness, and dispose a man to fancy great things concerning himself; they puff up. Therefore the prophet also said, “It is good for me, Lord, that You have afflicted me; that I may learn Your statutes.” When Hezekiah had received blessings and been freed from calamities, his heart was lifted up on high; when he fell sick, then was he humbled, then he became near to God. “When He slew them,” it says, “then they sought Him diligently, and turned, and were early in coming to God.” And again, “When the beloved waxed gross and fat, then he kicked.” For “the Lord is known when He executes judgments.”
9. Affliction is a great good. “Narrow is the way”, so that affliction thrusts us into the narrow [way]. He who is not pressed by affliction cannot enter. For he who afflicts himself in the narrow [way], is he who also enjoys ease; but he that spreads himself out, does not enter in, and suffers from being so to say wedged in. See how Paul enters into this narrow way. He “keeps under” his “body”, so as to be able to enter. Therefore, in all his afflictions, he continued giving thanks unto God. Have you lost your property? This has lightened you of the most of your wideness. Have you fallen from glory? This is another sort of wideness. Have you been falsely accused? Have the things said against you, of which you are nowise conscious to yourself been believed? “Rejoice and leap for joy.” For “blessed are you” (He says) “when men reproach you, and say all manner of evil against you, falsely, for My sake. Rejoice and be exceeding glad, for great is your reward in Heaven.”
Why do you marvel, if you are grieved, and wish to be set free from temptations? Paul wished to be set free, and oftentimes entreated God, and did not obtain. For the “thrice for this I besought the Lord,” is oftentimes; “and He said unto me, My grace is sufficient for you, for My strength is made perfect in weakness.” By “weakness,” he here means “afflictions.” What then? When he heard this he received it thankfully, and says, “Wherefore I take pleasure in infirmities”; that is, I am pleased, I rest in my afflictions. For all things then let us give thanks, both for comfort, and for affliction. Let us not murmur: let us not be unthankful. “Naked came I out of my mother's womb, naked also shall I depart.” You did not come forth glorious, do not seek glory. You were brought into life naked, not of money alone, but also of glory, and of honorable name.
Consider how great evils have oftentimes arisen from wealth. For “It is easier” (it is said) “for a camel to go through the eye of a needle, than for a rich man to enter into the kingdom of Heaven.” Do you see to how many good things wealth is a hindrance, and do you seek to be rich? Do you not rejoice that the hindrance has been overthrown? So narrow is the way which leads into the Kingdom. So broad is wealth, and full of bulk and swelling out. Therefore He says, “Sell that you have”, that that way may receive you. Why do you yearn after wealth? For this cause He took it away from you, that He might free you from slavery. For true fathers also, when a son is corrupted by some mistress, and having given him much exhortation they do not persuade him to part from her, send the mistress into banishment. Such also is abundance of wealth. Because the Lord cares for us, and delivers us from the harm [which arises] therefrom, He takes away wealth from us.
Let us not then think poverty an evil: sin is the only evil. For neither is wealth a good thing by itself: to be well-pleasing to God is the only good. Poverty then let us seek, this let us pursue: so shall we lay hold on heaven, so shall we attain to the other good things. Which may we all attain by the grace and lovingkindness of our Lord Jesus Christ, with whom to the Father together with the Holy Ghost be glory, power, honor, now and ever and world without end. Amen.
Source: Homilies on the Epistle to the Hebrews (New Advent)