Over at Called to Communion, Bryan Cross has an excellent article on the Sacrament of Marriage. Here’s a brief excerpt:
This doctrine is perceived by many people in our generation as scandalous, because divorce and remarriage have become so commonplace. The notion that divorce allows remarriage is rooted in a fundamental difference between the Protestant and Catholic doctrines concerning marriage. According to the Catholic Church, Christ raised marriage to the dignity of a sacrament. This means, among other things, that Christ did not merely remove Moses’s permission of divorce (Mt. 19:7-8; Mk. 10:3-4) and restore the original order of marriage (Mt. 19:6), while leaving married couples with no additional grace to live the married life. Rather, under the New Covenant the marriage of two baptized persons is accompanied by special grace from God such that the spouses may fulfill their marital and parental responsibilities in union with Christ and His Body, the Church. In this way, Christian marriage is an efficacious sign, communicating to the couple the grace it signifies regarding the indissoluble union of Christ and His Bride, the Church. It also makes Christian marriage (i.e. marriage between two baptized persons) a matter subject to the Church, because sacraments belong fundamentally to the stewardship of the Church.
But one of the Catholic doctrines that the first Protestants rejected is precisely the Catholic teaching that Christ raised marriage to the dignity of a sacrament. The inevitable consequence of this rejection is that in societies sufficiently influenced by Protestantism, marriage comes to be conceived and treated as merely a civil matter, and hence, by default, merely as a legal contract. As the Catholic Encyclopedia article on “Divorce” states regarding the practice and belief of the first Protestants, “Jurisdiction in matrimonial affairs was relegated, on principle, to the civil law, and only the blessing of marriage was assigned to the Church.” Of course many Protestant couples are wedded in a religious ceremony before a pastor in a church building, not before a judge. But because of the Protestant denial of the sacramental character of Christian marriage, what takes place during that ceremony, from the Protestant point of view, is still only the formation of a legal bond, one that the State has the authority to dissolve. . . .