25 Thus far, two essential facts have emerged from our reflections: a ) The Church's deepest nature is expressed in her three-fold responsibility: of proclaiming the word of God ( kerygma-martyria ), celebrating the sacraments ( leitourgia ), and exercising the ministry of charity ( diakonia ). These duties presuppose each other and are inseparable. For the Church, charity is not a kind of welfare activity which could equally well be left to others, but is a part of her nature, an indispensable expression of her very being. b ) The Church is God's family in the world. In this family no one ought to go without the necessities of life. Yet at the same time caritas- agape extends beyond the frontiers of the Church. The parable of the Good Samaritan remains as a standard which imposes universal love towards the needy whom we encounter “by chance” (cf. Lk 10:31), whoever they may be. Without in any way detracting from this commandment of universal love, the Church also has a specific responsibility: within the ecclesial family no member should suffer through being in need. The teaching of the Letter to the Galatians is emphatic: “So then, as we have opportunity, let us do good to all, and especially to those who are of the household of faith” (6:10).
Source: Deus Caritas Est (Vatican.va)