Editorial Note: This piece is published as a part of a symposium hosted by Patheos' Catholic Portal and Evangelical Portal, entitled, "For Life and Family: Faith and the Future of Social Conservatism."

The struggle against gay marriage in the United States is a lost cause, because the current American assumptions about democracy and the meaning of marriage are fundamentally incompatible with the Christian understanding of the nature of human beings and their sexual relationships. Moreover, the issue of gay marriage is not the most fundamental point of disagreement; that point was crossed many decades ago with the social acceptance of birth control, which altered social attitudes toward sex and over time encouraged sex completely divorced from love. It is therefore more important for Christians to develop a robust countercultural practice and reflection on sexuality, which is more life-giving than the weak legal understanding of marriage that prevails in popular opinion.

The current American assumption about marriage is that it involves two adults consenting to an economic partnership: an exchange of goods and services for mutual benefit. As such, the assumption includes the conviction that such partnerships ought to be protected by law: all couples should be able to have the same legal rights (inheritance, access to hospital records, tax breaks, and so on). Seen through the lens of American legal theory, this logic is correct, meaning that there ought to be no legal difference between gay and straight legal unions. Moreover, the assumption goes, there is a cultural meaning attached to the word "marriage," meaning that if some couples are allowed this meaning while others are not, there is prejudice. That logic is similarly correct.

The American assumption is weak, though, from a philosophical and cultural perspective, and wrong from a Christian theological perspective. The weakness lies in the fact that this logic about marriage is divorced from a philosophical or theological anthropology, rooting itself more in a model of law known as social contract. A social contract is basically an agreement among people about how they as a society will act. According to an American version of this theory, law is good if it reflects the will of the majority. And since the majority of people are coming to embrace the economic partnership model, the law ought to reflect that model. Over time, that model will likely have to include all sorts of legal partnerships as public opinion continues to change.

Historically, at least in the West, marriage was rooted in either a philosophical or theological anthropology (or both). One common version of the philosophical anthropology ran like this: government recognizes the social good of the partnerships of men and women raising children, and offers incentives (like tax breaks) to encourage this service to society.  It leverages the ordinary sexual desires of its citizens to work together for a social good. Broadly speaking, this philosophical anthropology was a modern version of the Natural Law theory that had its origins in ancient Greece (Stoic and Aristotelian philosophy, for example) and basically held that there was an overarching order (logos) in the world and that marriage reflected the ways that human beings structured themselves toward that order.