Traditionalists are losing the marriage debate today because we lost it several decades ago. Two recent articles in Public Discourse—both pitched as arguments against same-sex marriage—illustrate this. In each case, the real culprit is a policy that traditionalists have “gradually accommodated” despite deep conflict with Christian faith, the sanctity of marriage, and the welfare of children.

In “Dear Justice Kennedy: An Open Letter from the Child of a Loving Gay Parent,” Katy Faust describes the struggles growing up with her lesbian mom. Yet the real heart of her tragedy is her mother and father’s divorce, which she calls “the most traumatic event in my thirty-eight years of life.” Faust came of age years before same-sex marriage became legal, and her mother did not marry her lesbian partner. Faust writes eloquently of the pain of a missing parent; however, the public policy that separated her from her father was no-fault divorce, not same-sex marriage.

Janna Darnelle’s essay, “Breaking the Silence: Redefining Marriage Hurts Women Like Me - and Our Children,” is a moving account of her marriage to a man who hid his homosexuality from her, then revealed it almost ten years after their wedding. She wanted to save their marriage, but her husband left and sought custody of their children. Same-sex marriage was not legal in their state at that time. Once again, in terms of public policy, the source of this tragedy is no-fault divorce.

Marriage accomplishes many things, but one of its central purposes is to provide children with the stable and nurturing environment they need to flourish. A single mother trying to raise children alone will usually have much more difficulty accomplishing this than a mother who shares the task of raising her children with their father. Thus most human societies in most times and places have sought to discourage out-of-wedlock childbirth and to encourage stable marriages in which both parents share the burden of raising children.

It is no surprise that the advocates of the sexual revolution do not understand the logic behind the traditional human understanding of marriage. What is striking, however, is the confusion behind many traditionalist responses to the sexual revolution.

If we are concerned with children’s welfare, potentially procreative premarital and extra-marital sex are a much bigger concern than sodomy. The vast majority (85 percent) of children who are aborted were conceived out of wedlock. And of those who survive, children born out of wedlock are likely to be worse off on a wide range of measures than children raised by married parents.

Because of the potential to lead to procreative acts, heterosexual sodomy outside marriage is a greater concern than homosexual sodomy. Yet among these issues, traditionalists had until recently put most of their energy into defending laws punishing homosexual sodomy.

Laws that destabilize procreative marriage are much more destructive to children than laws that extend the benefits given to married couples to couples who cannot have children. The political scientist Mark Smith has written, “While many children could not even describe what it means to have an abortion or be gay or lesbian, they readily grasp—either firsthand or through the experiences of friends—the strained parental relationships and complicated custodial arrangements that often accompany divorce.” Yet there has been much more outcry against recognizing same-sex couples than there has been to no-fault divorce, which has separated millions of children from one of their parents, or forced them to shuttle back and forth from one parent to the other.

Children do not need a mother and a father; they need their mother and their father. Thanks to no-fault divorce, fathers and mothers—like husbands and wives—have been expendable for decades; until recently, however, the law required that the “replacement part” be of the same sex as the one cast off.

With the legalization of same-sex marriage, many Christians are concerned about the use of state power to coerce Christians who don’t support same-sex marriage. I share this concern. However, Jesus taught, “whoever divorces his wife, except for unchastity, and marries another, commits adultery; and he who marries a divorced woman, commits adultery.” When no-fault divorce laws passed, they not only radically redefined the terms of every existing marriage; they also placed adulterous liaisons on the same level, legally, as marriage. “Till death do us part” became “till one of us wants out.” When one spouse sued for divorce, the law took his side, even if the other spouse had not violated her vows and wanted to try to save the marriage. And “no fault” meant that the spouse who had violated his vows was at no disadvantage in seeking custody of the couple’s children.

If marriage is a lifelong union, this is the abolition of marriage.

I am concerned about laws that force Christians to participate in same-sex marriages against their conscience. But I am more concerned with the millions of Christians who have already been forced to divorce so that their spouse can pursue an adulterous relationship backed by the “full faith and credit” of the United States.

I don’t want to stir up the kind of apocalyptic fears of those involved in premarital sex and divorce that many Christians have stirred up regarding LGBT people. I simply want to invite Christians to listen to and learn to practice both Christ’s radical challenge to holiness and His radical mercy.