The Apostle Paul isn’t ambivalent about marriage. In replying to inquiries of the fledgling churches he helped plant, Paul instructs congregations to preserve purity, remain faithful to one another, and glory in the fact that marriage uniquely illustrates the relationship Christ shares with his own bride, the Church. Marriage is a covenant, and as a covenant the whole testimony of scripture from beginning to end tells us that God himself is the bonding seal. A covenant simply isn’t a covenant without God.

The narrative of the Old Testament follows a distinctly covenantal plotline. Here’s what I mean. God covenants with Abraham and his descendants, the people of Israel, establishing a new reality in which He will be their God and they will be his people. The unfolding story of ancient Israel is fairly cyclical—rebellion, judgment, exile, liberation, and reconciliation all over again, reminding Israel of the bond it shares with Yahweh, who is always faithful to the covenant. This is at least one reason why they call him Holy; he is always faithful to the covenant.

The Bible describes covenant as a promise between parties sealed by God. It differs from a contract in that it is fundamentally a theological and moral arrangement, not a legal one. In Abraham’s case, if he will but offer God his faith and obedience, God will enhance his life in every way and see that his descendants are as the stars in the sky. Covenants are the very bonds of relationships. Israel severs the covenant from its end, or attempts to, when it fails to believe and obey; God temporarily isn’t their God.

Christianity conceives of marriage as a covenantal relationship because, as an institution of the Church, it is a bond between two people sealed by God. The fact that it is God-sealed is absolutely pivotal. It places the emphasis not on the agreement between man and woman, but on God’s gracious power to solemnize and secure their oneness. Agreements waver; God is steadfast. Marital vows are impotent without God’s promise to help make them true.

The wedding ceremony expresses a decisive truth about the meaning of marriage—it is witnessed and thus supported by the community of faith, the Church. The minister who officiates is merely a representative formalizing the covenant and declaring its completeness as an act of worship. At the end of all the pomp and circumstance, more promises have been made than just the one between man and woman, for there are also the many promises of our brothers and sisters in Christ to help us along the way, and of course, most importantly, the promise of God to supervene until death doth part. In short, Christian marriage is a thoroughly ecclesial institution.

A contract, on the other hand, is a legal agreement between parties not to infringe upon the other party’s person or property. We have contracts because we do not trust one another enough to do without them. Legal dictionaries define “contract” as an agreement creating obligations enforceable by law. Naturally the implied “enforcer” here is the state. If you and I agree that I won’t destroy the property I rent from you, then I am liable if I do destroy it. Can we then think of marriage as a contract and also retain a biblical conception of marriage as covenant?

The answer is we can’t, not without draining it of its meaning. In marriage we promise to enhance and elevate the life of our spouse self-sacrificially. If we do not, we are subject to God’s corrective judgment. Thinking of the marriage relationship alternatively in contractual terms pushes God out and mistakenly assumes that the real mediator in marriage is the state. The error in this thinking is on vivid display these days in public debates about “civil unions.” Needless to say, civil unions, which are always contractual, do not enjoy the seal of God’s covenant. If marriage is a covenant, and the Bible claims uniformly that it is, then the power to seal marriages falls exclusively to God.