Can. 1055 §1. The matrimonial covenant, by which a man and a woman establish between themselves a partnership of the whole of life and which is ordered by its nature to the good of the spouses and the procreation and education of offspring, has been raised by Christ the Lord to the dignity of a sacrament between the baptized.
§2. For this reason, a valid matrimonial contract cannot exist between the baptized without it being by that fact a sacrament.
Can. 1056 The essential properties of marriage are unity and indissolubility, which in Christian marriage obtain a special firmness by reason of the sacrament.
"From a valid marriage arises a bond between the spouses which by its very nature is perpetual and exclusive; furthermore, in a Christian marriage the spouses are strengthened and, as it were, consecrated for the duties and the dignity of their state by a special sacrament." (CCC, 1638)
The consent by which the spouses mutually give and receive one another is sealed by God himself.143 From their covenant arises "an institution, confirmed by the divine law, . . . even in the eyes of society." The covenant between the spouses is integrated into God's covenant with man: "Authentic married love is caught up into divine love." (CCC, 1639)
Thus the marriage bond has been established by God himself in such a way that a marriage concluded and consummated between baptized persons can never be dissolved. This bond, which results from the free human act of the spouses and their consummation of the marriage, is a reality, henceforth irrevocable, and gives rise to a covenant guaranteed by God's fidelity. The Church does not have the power to contravene this disposition of divine wisdom. (CCC, 1640)
The sacrament of Matrimony signifies the union of Christ and the Church. It gives spouses the grace to love each other with the love with which Christ has loved his Church; the grace of the sacrament thus perfects the human love of the spouses, strengthens their indissoluble unity, and sanctifies them on the way to eternal life (cf. Council of Trent: DS 1799). (CCC, 1661)