Abstract. For the past two decades, I have been developing an integrative Christian marriage theory, based in part on a grounding concept of natural law and an overarching theory of covenant. The natural law part of this theory starts with an account of the natural facts, conditions, interests, needs, and qualities of human life, interaction, and generation—what I call the “premoral” goods or realities of life. It then identifies the natural inclinations of humans to form enduring and exclusive monogamous marriages and to preserve these units as the central site for intimacy, procreation, and nurture of children. In this paper, I first summarize this natural law theory of marriage and then compare it to the formulations of other modern Christian thinkers. I also defend this theory against various modern critics of natural law—in part by reinterpreting some traditional natural law teachings that in my view have been misunderstood, in part by looking at the interesting convergences between the insights into sex, marriage, and family life offered by contemporary Christian theological ethicists and by evolutionary biologists and biological anthropologists.