23 That the family may be established and maintained according to the wise teachings of the Gospel, therefore, the faithful should be frequently exhorted by those who have the directive and teaching functions in the churches, and these are to strive with unremitting care to present to the Lord a perfect people. For the same reason it is also supremely necessary to see to it that the dogma of the unity and indissolubility of matrimony is known in all its religious importance and sacredly respected by those who are to marry.
Source: Sertum Laetitiae (Vatican.va)