Catechism of the Catholic Church
2364 The married couple forms "the intimate partnership of life and love established by the Creator and governed by his laws; it is rooted in the conjugal covenant, that is, in their irrevocable personal consent." 147 Both give themselves definitively and totally to one another. They are no longer two; from now on they form one flesh. The covenant they freely contracted imposes on the spouses the obligation to preserve it as unique and indissoluble. 148 "What therefore God has joined together, let not man put asunder." 149
2365 Fidelity expresses constancy in keeping one's given word. God is faithful. The Sacrament of Matrimony enables man and woman to enter into Christ's fidelity for his Church. Through conjugal chastity, they bear witness to this mystery before the world.
St. John Chrysostom suggests that young husbands should say to their wives: I have taken you in my arms, and I love you, and I prefer you to my life itself. For the present life is nothing, and my most ardent dream is to spend it with you in such a way that we may be assured of not being separated in the life reserved for us.... I place your love above all things, and nothing would be more bitter or painful to me than to be of a different mind than you. 150
English Translation of the Cathechism of the Catholic Church for the United States of America © 1997, United States Catholic Conference, Inc.