Catechism of the Catholic Church

1609 In his mercy God has not forsaken sinful man. The punishments consequent upon sin, "pain in childbearing" and toil "in the sweat of your brow," ¹⁰⁰ also embody remedies that limit the damaging effects of sin. After the fall, marriage helps to overcome self-absorption, egoism, pursuit of one's own pleasure, and to open oneself to the other, to mutual aid and to self-giving.

1610 Moral conscience concerning the unity and indissolubility of marriage developed under the pedagogy of the old law. In the Old Testament the polygamy of patriarchs and kings is not yet explicitly rejected. Nevertheless, the law given to Moses aims at protecting the wife from arbitrary domination by the husband, even though according to the Lord's words it still carries traces of man's "hardness of heart" which was the reason Moses permitted men to divorce their wives. ¹⁰¹

1611 Seeing God's covenant with Israel in the image of exclusive and faithful married love, the prophets prepared the Chosen People's conscience for a deepened understanding of the unity and indissolubility of marriage. ¹⁰² The books of Ruth and Tobit bear moving witness to an elevated sense of marriage and to the fidelity and tenderness of spouses. Tradition has always seen in the Song of Solomon a unique expression of human love, insofar as it is a reflection of God's love - a love "strong as death" that "many waters cannot quench." ¹⁰³