Objection 1. It would seem that bishops sin mortally if they distribute not to the poor the ecclesiastical goods which they acquire. For Ambrose [Basil, Serm. lxiv, de Temp., among the supposititious works of St. Jerome] expounding Luke 12:16, "The land of a certain... man brought forth plenty of fruits," says: "Let no man claim as his own that which he has taken and obtained by violence from the common property in excess of his requirements"; and afterwards he adds: "It is not less criminal to take from him who has, than, when you are able and have plenty to refuse him who has not." Now it is a mortal sin to take another's property by violence. Therefore bishops sin mortally if they give not to the poor that which they have in excess.
Objection 2. Further, a gloss of Jerome on (Isaiah 3:14), "The spoil of the poor is in your house," says that "ecclesiastical goods belong to the poor." Now whoever keeps for himself or gives to others that which belongs to another, sins mortally and is bound to restitution. Therefore if bishops keep for themselves, or give to their relations or friends, their surplus of ecclesiastical goods, it would seem that they are bound to restitution.
Objection 3. Further, much more may one take what is necessary for oneself from the goods of the Church, than accumulate a surplus therefrom. Yet Jerome says in a letter to Pope Damasus [Cf. Can. Clericos, cause. i, qu. 2; Can. Quoniam; cause. xvi, qu. 1; Regul. Monach. iv, among the supposititious works of St. Jerome]: "It is right that those clerics who receive no goods from their parents and relations should be supported from the funds of the Church. But those who have sufficient income from their parents and their own possessions, if they take what belongs to the poor, they commit and incur the guilt of sacrilege." Wherefore the Apostle says (1 Timothy 5:1)6): "If any of the faithful have widows, let him minister to them, and let not the Church be charged, that there may be sufficient for them that are widows indeed." Much more therefore do bishops sin mortally if they give not to the poor the surplus of their ecclesiastical goods.
On the contrary, Many bishops do not give their surplus to the poor, but would seem commendably to lay it out so as to increase the revenue of the Church.
I answer that, The same is not to be said of their own goods which bishops may possess, and of ecclesiastical goods. For they have real dominion over their own goods; wherefore from the very nature of the case they are not bound to give these things to others, and may either keep them for themselves or bestow them on others at will. Nevertheless they may sin in this disposal by inordinate affection, which leads them either to accumulate more than they should, or not to assist others, in accordance with the demands of charity; yet they are not bound to restitution, because such things are entrusted to their ownership.
On the other hand, they hold ecclesiastical goods as dispensers or trustees. For Augustine says (Ep. clxxxv ad Bonif.): "If we possess privately what is enough for us, other things belong not to us but to the poor, and we have the dispensing of them; but we can claim ownership of them only by wicked theft." Now dispensing requires good faith, according to 1 Corinthians 4:2, "Here now it is required among the dispensers that a man be found faithful." Moreover ecclesiastical goods are to be applied not only to the good of the poor, but also to the divine worship and the needs of its ministers. Hence it is said (XII, qu. ii, can. de reditibus): "Of the Church's revenues or the offerings of the faithful only one part is to be assigned to the bishop, two parts are to be used by the priest, under pain of suspension, for the ecclesiastical fabric, and for the benefit of the poor; the remaining part is to be divided among the clergy according to their respective merits." Accordingly if the goods which are assigned to the use of the bishop are distinct from those which are appointed for the use of the poor, or the ministers, or for the ecclesiastical worship, and if the bishop keeps back for himself part of that which should be given to the poor, or to the ministers for their use, or expended on the divine worship, without doubt he is an unfaithful dispenser, sins mortally, and is bound to restitution.
But as regards those goods which are deputed to his private use, the same apparently applies as to his own property, namely that he sins through immoderate attachment thereto or use thereof, if he exceeds moderation in what he keeps for himself, and fails to assist others according to the demands of charity.
On the other hand, if no distinction is made in the aforesaid goods, their distribution is entrusted to his good faith; and if he fail or exceed in a slight degree, this may happen without prejudice to his good faith, because in such matters a man cannot possibly decide precisely what ought to be done. On the other hand, if the excess be very great he cannot be ignorant of the fact; consequently he would seem to be lacking in good faith, and is guilty of mortal sin. For it is written (Matthew 24:48-51) that "if that evil servant shall say in his heart: My lord is long a-coming," which shows contempt of God's judgment, "and shall begin to strike his fellow-servants," which is a sign of pride, "and shall eat and drink with drunkards," which proceeds from lust, "the lord of that servant shall come in a day that he hopeth not... and shall separate him," namely from the fellowship of good men, "and appoint his portion with hypocrites," namely in hell.
Reply to Objection 1. This saying of Ambrose refers to the administration not only of ecclesiastical things but also of any goods whatever from which a man is bound, as a duty of charity, to provide for those who are in need. But it is not possible to state definitely when this need is such as to impose an obligation under pain of mortal sin, as is the case in other points of detail that have to be considered in human acts: for the decision in such matters is left to human prudence.
Reply to Objection 2. As stated above the goods of the Church have to be employed not only for the use of the poor, but also for other purposes. Hence if a bishop or cleric wish to deprive himself of that which is assigned to his own use, and give it to his relations or others, he sins not so long as he observes moderation, so, to wit, that they cease to be in want without becoming the richer thereby. Hence Ambrose says (De Offic. i, 30): "It is a commendable liberality if you overlook not your kindred when you know them to be in want; yet not so as to wish to make them rich with what you can give to the poor."
Reply to Objection 3. The goods of churches should not all be given to the poor, except in a case of necessity: for then, as Ambrose says (De Offic. ii, 28), even the vessels consecrated to the divine worship are to be sold for the ransom of prisoners, and other needs of the poor. On such a case of necessity a cleric would sin if he chose to maintain himself on the goods of the Church, always supposing him to have a patrimony of his own on which to support himself.
Reply to Objection 4. The goods of the churches should be employed for the good of the poor. Consequently a man is to be commended if, there being no present necessity for helping the poor, he spends the surplus from the Church revenue, in buying property, or lays it by for some future use connected with the Church or the needs of the poor. But if there be a pressing need for helping the poor, to lay by for the future is a superfluous and inordinate saving, and is forbidden by our Lord Who said (Matthew 6:34): "Be... not solicitous for the morrow."
Source: Summa Theologica (New Advent)