When even Christianity Today is asking, “Is the Gay Marriage Debate Over?” the issue has become so critical that it demands close attention. Believing (wrongly) that the debate is over, some evangelicals have decided that Christians should let the state define marriage any way it chooses and focus their attention only on what the Church does. This would be a fundamental mistake. The debate is one in which we must be involved for the sake of our society itself. Even a state such as ours, which does not use the law to promote or discourage particular religious beliefs, nevertheless has a huge stake in marriage. It is not simply a religious issue. The law is a moral teacher. Most people assume that if something is legal, it is moral”or at least not immoral. What is legal soon will become normal. Every society requires an ongoing supply of babies who grow up to be good citizens. Every civilization has known what contemporary sociologists now demonstrate: Children grow best into wholesome adults when they live with their biological mother and father. Marriage law is a crucial way in which the state promotes the sound nurturing of the next generation of citizens.

Legalizing gay marriage would weaken the connection between marriage and procreation”and the connection between biological parents and their biological children”which is why court cases in support of gay marriage typically downgrade the role of procreation. The Massachusetts Supreme Court said that the state is indifferent to family structure. When Canada legalized same-sex marriage, it tossed out the definition of “natural” parent and replaced it with “legal” parent.

Most legal scholars agree that if gay marriage receives the sanction of law, “gay rights” will be pitted against the rights of religious freedom”and, more often than not, will win. Gay activists will argue that government cannot “subsidize discrimination,” and the courts will generally agree. Religious institutions will find that freedom to practice and even say what they believe about sexuality and marriage will increasingly be restricted. Already, in Canada and Sweden, pastors have been taken to court and charged with hate crimes because they preached sermons condemning homosexual practice as sin.

Nobody thinks churches or ministers will be forced to marry gay couples”although they may lose their legal privilege to register marriages if they refuse to do so. But through licensure and government grants a wide variety of faith-based organizations will face growing pressure to abandon their stand on homosexual practice and gay marriage.

There already are significant examples. More than twenty years ago, when a gay student group sued Georgetown University for refusing to grant it university recognition, the D.C. Court of Appeals concluded that “the eradication of sexual orientation discrimination outweighs any burden imposed upon Georgetown’s exercise of religion.” Massachusetts has required that Catholic Charities’ long-established adoption program must place children with gay couples”even if the program receives no money from the commonwealth. The New York Court of Appeals ruled against Yeshiva University because it refused to permit a same-sex couple to live in its married-student housing. In San Francisco, the Salvation Army lost $3.5 million in social-service contracts because it refused, on religious grounds, to provide benefits to same-sex partners of its employees.

Faith-based organizations eventually may lose their tax-exempt status. Even the threat of such a disastrous development will move many Christian organizations to silence or change. In 1983, the Supreme Court ruled that Bob Jones University could lawfully be denied its tax exemption because of its policy on interracial dating. I vigorously agree with that decision because racism is wrong. But more and more people accept the misguided argument that opposition to homosexual practice and gay marriage is just like racism.

Tragically, because of our own mistakes and sin, we evangelicals have almost no credibility on this topic. We have tolerated genuine hatred of gays; we should have taken the lead in condemning gay bashing but were largely silent; we have neglected to act in gentle love with people among us struggling with their sexual identity; and we have used the gay community as a foil to raise funds for political campaigns. We have made it easy for the media to suggest that the fanatics who carry signs announcing “God hates fags” actually speak for large numbers of evangelicals.

Worst of all, we have failed to deal honestly with the major threat to marriage and the family: heterosexual adultery and divorce. Evangelicals divorce at the same rate as the rest of the population. Many evangelical leaders have failed to speak against cheap divorce because they and their people were getting divorced just like everyone else. And yet we have had the gall to use the tiny (5 percent or less) gay community as a whipping boy that we labeled as the great threat to marriage.

What a farce. It is hardly surprising that young non-Christians’ most common perception (held by 91 percent) of contemporary Christianity is that we are “antihomosexual.” Even more disturbing is that 80 percent of young churchgoers agree.

We did not need to do this. We could have preached against hatred of gays, taken the lead in combating gay bashing, and been the most active community lovingly caring for people with AIDS. We could have taken marriage more seriously. We could have shown the world that Christians could defend marriage while loving those who wanted to live a different way.

The former vice president of Jerry Falwell’s Liberty University, Ed Dobson, got it right. After he left Liberty to become pastor of Calvary Church in Grand Rapids, Michigan, he regularly visited a former parishioner’s hospitalized son who turned out to have AIDS. Slowly, he sensed a call to serve other people with AIDS.

He decided to visit the local AIDS resource center run by the gay community. The director was shocked that the pastor of the largest evangelical church in town would visit. Dobson’s church was soon deeply engaged with the gay community. Calvary placed a church member on the board of the AIDS resource center, bought Christmas gifts for families affected by AIDS, paid for funeral expenses for impoverished people who died of AIDS, and welcomed the gay community to attend the church.

Of course, it was controversial. One church member warned that the church would be “overrun by homosexuals.” Dobson responded in his next Sunday sermon: “If the church gets overrun with homosexuals, that will be terrific. They can take their place in the pews right next to the liars, gossips, and materialists.”

Most astonishing was an editorial that appeared in the local gay and lesbian newsletter. The writer noted that Dobson and Calvary Church believed gay sexual activity was sinful, but thanked Calvary Church for inviting gays and lesbians to their services. They knew that Dobson and his church loved them because they ministered to the people dying of AIDS.

Think of the impact if most evangelicals in the past three decades had followed Dobson’s example. Then, maybe, when non-Christians heard the word “evangelical,” they would think, “Oh, they are the people who love homosexuals and care for them when they are dying of AIDS.” Tragically, as Dobson says, we have been better at hating than loving. As a consequence, we cannot respond effectively, with any public credibility, to the challenge to the historic understanding of marriage.

The challenge is a great one. Many Americans, including substantial numbers of evangelical youth, ask: How does granting a state marriage license to that 5 percent of the population that is gay hurt the 95 percent that is heterosexual? How can we deny the rights and privileges of marriage to gay people without violating the principles of justice, equality, and respect for individual freedom? Many Americans embrace the libertarian principle that we should maximize the freedom of each individual except where that harms others, and most believe that marriage is “primarily a way in which two adults affirm their emotional commitment to one another,” as gay activist Andrew Sullivan has written.

If that is the proper definition of marriage, it is indeed unfair for the state to deny that privilege to a few when it grants it to the majority. But everything depends on the definition. If marriage is not about bringing up children, but about how adults solemnize their emotional commitment to each other, gay marriage becomes plausible. Other relationships become plausible as well. Why should marriage be limited to two people, for example? In fact, in 2006, prominent pro-gay activists, including Gloria Steinem and professors at Yale and Columbia, urged the state to recognize polygamous marriages and relationships of multiple sex partners.

Is emotional commitment between two adults what the state should care about in marriage? What should a state that does not establish any religion understand marriage to be? I think the answer is clear. The state must promote the best setting in which to nurture the next generation of wholesome citizens.

In a fascinating article in the Public Interest called “The Liberal Case Against Gay Marriage,” Susan Shell argues that the state’s central concern is to secure “the relation between a child and a particular set of parents.” In marriage, Shell notes, “A husband is, until otherwise proven, the acknowledged father of his wife’s offspring, with recognized rights and duties that may vary from society to society but always exist in some form. And a wife is a woman who can expect a certain specified sort of help from her husband in the raising of her offspring. All other functions of marriage borrow from or build upon this one.”

She asks: “Can those who are not even potentially partners in reproduction, and who could never under any circumstances have been so, actually ‘marry’?” Her answer is no. Whatever else one may want to say positively about the emotional commitment of two men or two women to each other, it is simply not marriage. If the central concern of the state in marriage law is to secure a good relationship between a child and its biological parents, then by definition marriage can only involve a man and a woman.

Other things being equal, it is better for children to grow up with their biological parents. Marriage to the mother is by far the best way to ensure responsible fatherhood. When not married to the mother, few men are effective fathers. As far as the state is concerned, the first concern of marriage law must be to protect the interests of children and thereby create an ongoing, stable, wholesome social order.

It has been argued that, if the state’s central interest in marriage is the raising of wholesome citizens, it should not grant a marriage license to sterile couples, those who choose not to have children, or older people who no longer can conceive children. Because the advocates of traditional marriage will not say this, the argument goes, their claims are invalid.

In fact, we do not say this because our argument actually does not imply it. The state cannot know which married men and women will be sterile. By granting couples who do not want children the status of marriage, the state recognizes that they have the kind of union that characteristically produces children, even if they choose (at first) not to have any. By granting that status to older people no longer capable of conceiving a child, the state encourages the view that sex should be limited to married persons because that strengthens the likelihood that children will be raised by their biological parents.

It also has been argued that arguments along these lines belittle adoption. My wife and I have a wonderful adopted daughter. In many situations (including abuse, neglect, and financial deprivation), adoption is much better for a child than remaining with one or both biological parents”but that does not change the fact that, other things being equal, it is better for a child to grow up with both biological parents. Even the best adoptive homes recognize that the absence of biological parents brings painful struggles.

Many gay partners argue that their home is just as good for children as that of a married man and woman. We do not have the careful, longitudinal comparative studies needed to demonstrate whether they are right or wrong, but we know that adopted children in even the best families experience emotional anguish at the loss of their biological parents, and family-systems studies show that adolescents develop their own sexual identity best when they have both male and female role models. It is certainly reasonable, on the basis of what we now know, to make the claim that, other things being equal, it is better for children to grow up with both biological parents.

Some also argue that it is better for a child to be adopted by gay partners than to grow up in an orphanage or poor foster home. But even if it were, that does not warrant changing the historic definition of marriage.

The evidence, as we have seen, is clear: The legal redefinition of marriage would have far-reaching negative consequences. Abandoning what every civilization for millennia has understood marriage to be would harm children and undermine religious freedom. What can we evangelicals, who have lost almost all our credibility to speak on this topic, do to promote the historic understanding of marriage?

First, we must truly repent of the deep, widespread antigay prejudice in evangelical circles. We must ask forgiveness for our failures of love and concern and stop elevating the sin of homosexual practice above other sins.

In the life of the local church, we must distinguish homosexual orientation and practice. Someone who is publicly known to have a gay orientation but lives a celibate life should be just as eligible for church leadership as a heterosexual person who has been promiscuous but now lives in a faithful heterosexual marriage or remains celibate. We should develop church settings where celibate persons with a gay orientation can experience strong, supportive Christian community.

Second, we must set our own house in order by dramatically reducing in our families the devastation and havoc caused by heterosexual disobedience. Our argument that the tiny gay community undermines marriage is hypocritical unless we admit that by far the greatest threat to marriage and family is the sinful failure of husbands and wives to keep their marriage vows. If we cannot resist adultery and divorce and model wholesome, joyful family life, we should admit that we have nothing credible to say in the public discussion of marriage.

Almost everyone longs for something better. Jesus’ followers know the answer to that longing. Evangelical husbands and wives who keep their marriage vows for a lifetime and raise their biological (and adopted) children in joyful, wholesome families would be one of our most powerful evangelistic tools. They would also give us credibility when we promote the historic understanding of marriage.

To do this we will need to teach biblical truths on sexuality, marriage, and divorce at every level, from preteens through retirees. We will need extensive Christian marriage counseling and programs such as Marriage Savers. We will need to resist the culture’s narcissistic individualism, already too visible in our churches, and develop congregations that are communities of mutual accountability and even church discipline”in the wonderful words of John Wesley, “Watching over one another in love.”

Third, we should seek to change the divorce laws, especially no-fault divorce. When children are involved, the law should deny no-fault divorce and in other ways make divorce more difficult. This, not gay marriage, is the area of marriage law that affects the vast majority of our children. We should be spending the overwhelming majority of the time we devote to marriage law to changing the law that permits cheap divorce for heterosexuals.

Finally, we must treat gay people fairly. Gay couples want to have, and deserve to have, such basic rights as that of the family member or spouse to visit a loved one in the hospital. One significant way to give them these rights would be to support the legal recognition of civil unions. (These unions also should be available to such others as a single person looking after an aging parent or a bachelor brother and spinster sister running a business together.)

Other legal procedures might meet gay people’s concerns. But I see no problem with a carefully written law that defines a number of rights as part of a legally recognized civil union. That does not mean that those rights should include everything but the name of marriage. Given the purpose of marriage law, some rights and benefits”specifically those designed to strengthen the likelihood that children grow up with both biological parents”belong only to those who are married and not to those in civil unions. That would be fair, and also a test. If the gay community’s real agenda is to legitimize the homosexual lifestyle, the community will reject civil unions. If the agenda is, as many now claim, to gain appropriate benefits and rights, the gay community will accept civil unions and not press for gay marriage.

Ron Sider is president of Evangelicals for Social Action and professor of theology, holistic ministry, and public policy at Palmer Seminary at Eastern University.