14 Now, the training of youth most conducive to the defense of true faith and religion and to the preservation of morality must find its beginning from an early stage within the circle of home life; and this family Christian training sadly undermined in these our times, cannot possibly be restored to its due dignity, save by those laws under which it was established in the Church by her Divine Founder Himself. Our Lord Jesus Christ, by raising to the dignity of a sacrament the contract of matrimony, in which He would have His own union with the Church typified, not only made the marriage tie more holy, but, in addition, provided efficacious sources of aid for parents and children alike, so that, by the discharge of their duties one to another, they might with greater ease attain to happiness both in time and in eternity. But when impious laws, setting at naught the sanctity of this great sacrament, put it on the same footing of mere civil contracts, the lamentable result followed, that, outraging the dignity of Christian matrimony, citizens made use of legalized concubinage in place of marriage; husband and wife neglected their bounden duty to each other; children refused obedience and reverence to their parents; the bonds of domestic love were loosened; and alas! the worst scandal and of all the most ruinous to public morality, very frequently an unholy passion opened the door to disastrous and fatal separations. These most unhappy and painful consequences, venerable brothers, cannot fail to arouse your zeal and move you constantly and earnestly to warn the faithful committed to your charge to listen with docility to your teaching regarding the holiness of Christian marriage, and to obey laws by which the Church controls the duties of married people and of their offspring.(10)
Source: Inscrutabili Dei Consilio (Vatican.va)