44 And here We wish, Venerable Brethren, to insist more particularly on two teachings of Our Lord which have a special bearing on the present condition of the human race: detachment from earthly goods and the precept of charity. "Blessed are the poor in spirit" were the first words that fell from the lips of the Divine Master in His sermon on the mount. This lesson is more than ever necessary in these days of materialism athirst for the goods and pleasures of this earth. All Christians, rich or poor, must keep their eye fixed on heaven, remembering that "we have not here a lasting city, but we seek one that is to come." The rich should not place their happiness in things of earth nor spend their best efforts in the acquisition of them. Rather, considering themselves only as stewards of their earthly goods, let them be mindful of the account they must render of them to their Lord and Master, and value them as precious means that God has put into their hands for doing good; let them not fail, besides, to distribute of their abundance to the poor, according to the evangelical precept. Otherwise there shall be verified of them and their riches the harsh condemnation of St. James the Apostle: "Go to now, ye rich men; weep and howl in your miseries which shall come upon you. Your riches are corrupted, and your garments are moth-eaten; your gold and silver is cankered; and the rust of them shall be for a testimony against you and shall eat your flesh like fire. You have stored up to yourselves wrath against the last days. . ."
Source: Divini Redemptoris (Vatican.va)