8 While every exercise of the apostolate should be motivated by charity, some works by their very nature can become specially vivid expressions of this charity. Christ the Lord wanted these works to be signs of His messianic mission (cf. Matt. 11:4-5). The greatest commandment in the law is to love God with one's whole heart and one's neighbor as oneself (cf. Matt. 22:37-40). Christ made this commandment of love of neighbor His own and enriched it with a new meaning. For He wanted to equate Himself with His brethren as the object of this love when He said, "As long as you did it for one of these, the least of My brethren, you did it for Me" (Matt. 25:40). Assuming human nature, He bound the whole human race to Himself as a family through a certain supernatural solidarity and established charity as the mark of His disciples, saying, "By this will all men know that you are My disciples, if you have love for one another" (John 13:35). ln her very early days, the holy Church added the agape to the eucharistic supper and thus showed itself to be wholly united around Christ by the bond of charity. So, too, in every era it is recognized by this sign of love, and while it rejoices in the undertakings of others, it claims works of charity as its own inalienable duty and right. For this reason, pity for the needy and the sick and works of charity and mutual aid intended to relieve human needs of every kind are held in highest honor by the Church. At the present time, with the development of more rapid facilities for communication, with the barrier of distance separating men greatly reduced, with the inhabitants of the entire globe becoming one great family, these charitable activities and works have become more urgent and universal. These charitable enterprises can and should reach out to all persons and all needs. Wherever there are people in need of food and drink, clothing, housing, medicine, employment, education; wherever men lack the facilities necessary for living a truly human life or are afflicted with serious distress or illness or suffer exile or imprisonment, there Christian charity should seek them out and find them, console them with great solicitude, and help them with appropriate relief. This obligation is imposed above all upon every prosperous nation and person. In order that the exercise of charity on this scale may be unexceptionable in appearance as well as in fact, it is altogether necessary that one should consider in one's neighbor the image of God in which he has been created, and also Christ the Lord to Whom is really offered whatever is given to a needy person. It is imperative also that the freedom and dignity of the person being helped be respected with the utmost consideration, that the purity of one's charitable intentions be not stained by seeking one's own advantage or by striving for domination, and especially that the demands of justice be satisfied lest the giving of what is due in justice be represented as the offering of a charitable gift. Not only the effects but also the causes of these ills must be removed and the help be given in such a way that the recipients may gradually be freed from dependence on outsiders and become self-sufficient. Therefore, the laity should hold in high esteem and, according to their ability, aid the works of charity and projects for social assistance, whether public or private, including international programs whereby effective help is given to needy individuals and peoples. In so doing, they should cooperate with all men of good will.
Source: Apostolicam Actuositatem (Vatican.va)