From: James 5:1-6
A Warning for the Rich
 Come now, you rich, weep and howl for the miseries that are coming upon you.  Your riches have rotted and your garments are moth-eaten.  Your gold and silver have rusted, and their rust will be evidence against you and will eat your flesh like fire. You have laid up treasures for the last days.  Behold, the wages of the laborers who mowed your fields, which you kept back by fraud, cry out and the cries of the harvesters have reached the ears of the Lord of hosts.  You have lived on the earth in luxury and in pleasure; you have fattened your hearts in a day of slaughter.  You have condemned, you have killed the righteous man; he does not resist you.
1-6. With exceptional severity and energy the sacred writer again (cf. 2:5-7) criticizes the sins of the well-to-do. In tones reminiscent of the Prophets (cf., e.g., Is 3:13-26; Amos 6:1ff; Mic 2:1ff), he reproves their pride, vanity and greed (vv. 2-3) and their pleasure-seeking (v. 5), warning them that the judgment of God is near at hand (vv. 3, 5). The opening exhortation--"weep and howl"--is a very forceful call to repentance.
The Church has constantly taught that we have a duty to do away with unjust inequalities among men, which are frequently denounced in Scripture. The Second Vatican Council made an urgent call for a more just, fraternal society, a call for solidarity: "To fulfill the requirements of justice and equity, every effort must be made to put an end as soon as possible to the immense economic inequalities which exist in the world and increase from day to day, linked with individual and social discrimination, provided, of course, that the rights of individuals and the character of each people are not disturbed" ("Gaudium Et Spes", 66).
People who are well-to-do should use their resources in the service of others. In this connection, the Church teaches that "they have a moral obligation not to keep capital unproductive and in making investments to think first of the common good. [...] The right to private property is inconceivable without responsibilities to the common good. It is subordinated to the higher principle which states that goods are meant for all" (SCDF, "Libertatis Conscientia", 87).
2-3. Greed, an inordinate desire for material things, is one of the seven deadly sins. An avaricious person offends against justice and charity and becomes insensitive to the needs of his neighbor, so keen is he on his self-aggrandizement. "If you are inclined to avarice," say St Francis de Sales, "think of its folly: it makes us slaves to that which was intended to serve us. Remember how we must leave everything when we die; perhaps those who get our wealth then will only squander it, and even to their ruin" ("Introduction to the Devout Life", 4, 10).
Our Lord also speaks about the moth and the rust which consume earthly treasures, and tells us that the true treasure is good works and upright actions, which will earn us an everlasting reward from God in heaven (cf. Mt 6:19-21).
"You have laid up treasure for the last days": a reference to the Day of Judgment, as in v. 5: "you have fattened your hearts in a day of slaughter" (cf. e.g., Is 34:6; Jer 12:3; 25:34). It can also be translated as "you have laid up treasure in the last days", which would be a reference to the present time, which (ever since the coming of the Messiah) is seen as in fact the last days, the beginning of the eschatological era. The two renderings are compatible because they both have reference to the Judgment.
4. Cheating workers of their earnings was already condemned in the Old Testament (cf., e.g., Lev 19:13; Deut 24:14-15; Mal 3:5). It is one of the sins which "cries out to heaven" for immediate, exemplary punishment; the same applies to murder (cf. Gen 4:10), sodomy (Gen 18:20-21) and oppression of widows and orphans (Ex 22:22-24).
The Church has often reminded the faithful about the duty to pay fair wages: "remuneration for work should guarantee man the opportunity to provide a dignified livelihood for himself and his family on the material, social, cultural and spiritual level to correspond to the role and the productivity of each, the relevant economic factors in his employment, and the common good" (Vatican II, "Gaudium Et Spes", 67).
"The Lord of hosts": a common Old Testament description of God, manifesting his omnipotence, as Creator and Lord of the whole universe; it is used to acclaim God in the Sanctus of the Mass: "Lord God of power and might" ("Dominus Deus Sabaoth").
5. This description of the lifestyle of these rich people (vv. 2, 3, 5) recalls the parable of the rich man and Lazarus (cf. Lk 16: 19ff). Those who live in this way do well to listen to the Master's warning: "Take heed to yourselves lest your hearts be weighed down with dissipation and drunkenness and cares of this life, and that day come upon you suddenly like a snare" (Lk 21:34).
Against the hedonism condemned by the sacred writer, Christians should be conscious of the duty to promote a just society: "Christians engaged actively in modern economic and social progress and in the struggle for justice and charity must be convinced that they have much to contribute to the prosperity of mankind and to world peace. Let them, as individuals and as group members, give a shining example to others. Endowed with the skill and experience so absolutely necessary for them, let them preserve a proper sense of values in their earthly activity in loyalty to Christ and his Gospel, in order that their lives, individual as well as social, may be inspired by the spirit of the Beatitudes, and in particular by the spirit of poverty.
"Anyone who in obedience to Christ seeks first the kingdom of God will derive from it a stronger and purer love for helping all his brethren and for accomplishing the task of justice under the inspiration of charity" ("Gaudium Et Spes", 72).
6. "The righteous man": according to St Bede (cf. "Super Iac. Expositio, ad loc."), this refers to our Lord, who is just "par excellence" and is described as such in other passages of Scripture (cf., e.g., Acts 3:14; 7:52). This interpretation is quite appropriate, given the fact that in the needy we should see Jesus Christ himself (cf. Mt 25:31-45); they often suffer at the hands of those who refuse to recognize even their most elementary rights: "The bread of the needy is the life of the poor, whoever deprives them of it is a man of blood. To take away a neighbor's living is to murder him; to deprive an employee of his wages is to shed blood" (Sir 34:21-22).
"Every man has the right to possess a sufficient amount of the earth's goods for himself and his family. This has been the opinion of the Fathers and Doctors of the Church, who taught that men are bound to come to the aid of the poor and to do so not merely out of their superfluous goods [...] Faced with a world today where so many people are suffering from want, the Council asks individuals and governments to remember the saying of the Fathers: 'Feed the man dying of hunger, because if you do not feed him you are killing him!' and it urges them according to their ability to share and dispose of their goods to help others, above all by giving them aid which will enable them to help and develop them selves' ("Gaudium Et Spes", 69).
Source: "The Navarre Bible: Text and Commentaries". Biblical text taken from the Revised Standard Version and New Vulgate. Commentaries made by members of the Faculty of Theology of the University of Navarre, Spain. Published by Four Courts Press, Kill Lane, Blackrock, Co. Dublin, Ireland. Reprinted with permission from Four Courts Press and Scepter Publishers, the U.S. publisher.