Christ the Lord abundantly blessed this many-faceted love [between a husband and wife], welling up as it does from the fountain of divine love and structured as it is on the model of his union with his church.
For as God of old made himself present to his people through a covenant of love and fidelity, so now the Savior of men and women and the Spouse of the church comes into the lives of married Christians through the Sacrament of Matrimony.
Authentic married love is caught up into divine love and is governed and enriched by Christ’s redeeming power and the saving activity of the church, so that this love may lead the spouses to God with powerful effect and may aid and strengthen them in the sublime office of being a father or a mother. For this reason, Christian spouses have a special sacrament by which they are fortified and receive a kind of consecration in the duties and dignity of their state. By virtue of this sacrament, as spouses fulfill their conjugal and family obligation, they are penetrated with the Spirit of Christ, which suffuses their whole lives with faith, hope, and charity. Thus they increasingly advance the perfection of their own personalities, as well as their mutual sanctification, and hence contribute jointly to the glory of God.
As members of the family, children contribute in their own way to making their parents holy. For they will respond to the kindness of their parents with sentiments of gratitude, with love and trust. They will stand by them as children should when hardships overtake their parents and old age brings its loneliness. . . . Families too will share their spiritual riches generously with other families. Thus the Christian family, which springs from marriage as a reflection of the loving covenant uniting Christ with the church, and as a participation in that covenant, will manifest to everyone Christ’s living presence in the world, and the genuine nature of the church. This the family will do by the mutual love of the spouses, by their generous fruitfulness, their solidarity and faithfulness, and by the loving way in which all members of the family assist one another.
(On the Church in the Modern World, 48)