The Second Vatican Council placed special emphasis on the term "covenant" to describe the unbreakable union of husband and wife (GS 48; 50). Even on the level of its natural institution, the indissolubility of marriage images the absolutely faithful character of God's love for humankind, a love which was to find very special expression in the covenant which, through Abraham (Gen 17:1-2) and Moses (Ex 19:5), he made with his Chosen People.
When Jesus Christ raised marriage to the level of a sacrament, indissolubility took on a new significance, becoming a sign of the love - faithful to death - of Christ for his Church. So indissolubility in christian marriage is said to acquire "a special firmness by reason of the sacrament" (c. 1056).
The expression "goods" (or "bona") of marriage originated with St. Augustine, one of the leading figures in the history of Western thought. Augustine used the expression "bona" (plural of the Latin "bonum") in the rich and significant sense of "values" or "blessings". It is important not to overlook this, since subsequent use down the centuries, especially in the field of church law, has tended to narrow its meaning and make it appear to be a term of purely technical interest just for canonists. In order to understand its scope, it is important to recall the context in which St. Augustine utilized it.
Many complexities and difficulties accompany "mixed marriages", i.e. between a Catholic and a baptized non-Catholic. These difficulties, the Catechism says, "must not be underestimated. They arise from the fact that the separation of Christians has not yet been overcome. The spouses risk experiencing the tragedy of Christian disunity even in the heart of their own home" (1634). According to Church law, such marriages cannot be licitly contracted without the express permission of the proper authority (usually the local bishop), who is not to grant it unless the Catholic party is ready to protect his or her own faith and sincerely promises to do all in their power to have the children baptized and educated as Catholics (cf. cc. 1124-25).
The book of Genesis contains two accounts of the creation of the sexes and the institution of marriage. "God created man in his own image...; male and female he created them. And God blessed them, and God said to them, 'Be fruitful and multiply'" (Gn 1:27-28). "Then the Lord God said, 'It is not good that the man should be alone: I will make him a helper fit for him'... [and God made woman]. Then the man said, 'This at last is bone of my bones and flesh of my flesh'... Therefore a man leaves his father and his mother and cleaves to his wife, and they become one flesh" (Gn 2:18-24).