26 If, then, we consider the end of the divine institution of marriage, we shall see very clearly that God intended it to be a most fruitful source of individual benefit and of public welfare, Not only, in strict truth, was marriage instituted for the propagation of the human race, but also that the lives of husbands and wives might be made better and happier. This comes about in many ways: by their lightening each other's burdens through mutual help; by constant and faithful love; by having all their possessions in common; and by the heavenly grace which flows from the sacrament. Marriage also can do much for the good of families, for, so long as it is conformable to nature and in accordance with the counsels of God, it has power to strengthen union of heart in the parents; to secure the holy education of children; to temper the authority of the father by the example of the divine authority; to render children obedient to their parents and servants obedient to their masters. From such marriages as these the State may rightly expect a race of citizens animated by a good spirit and filled with reverence and love for God, recognizing it their duty to obey those who rule justly and lawfully, to love all, and to injure no one.
Source: Arcanum Divinae (Vatican.va)