63 In regard to the Church, her cooperation will never be found lacking, be the time or the occasion what it may; and she will intervene with all the greater effect in proportion as her liberty of action is the more unfettered. Let this be carefully taken to heart by those whose office it is to safeguard the public welfare. Every minister of holy religion must bring to the struggle the full energy of his mind and all his power of endurance. Moved by your authority, venerable brethren, and quickened by your example, they should never cease to urge upon men of every class, upon the high-placed as well as the lowly, the Gospel doctrines of Christian life; by every means in their power they must strive to secure the good of the people; and above all must earnestly cherish in themselves, and try to arouse in others, charity, the mistress and the queen of virtues. For, the happy results we all long for must be chiefly brought about by the plenteous outpouring of charity; of that true Christian charity which is the fulfilling of the whole Gospel law, which is always ready to sacrifice itself for others' sake, and is man's surest antidote against worldly pride and immoderate love of self; that charity whose office is described and whose Godlike features are outlined by the Apostle St. Paul in these words: "Charity is patient, is kind, . . . seeketh not her own, . . . suffereth all things, . . . endureth all things."(41)
Source: Rerum Novarum (Vatican.va)