This article from Ryan T. Anderson in National Review provides leadership.

Excerpt:

In the short run, the legal battle over the definition of marriage may be an uphill struggle. But in the long run, those who defend marriage as the union of a man and woman will prove to be prophetic. First, because when people do hear a compelling case for marriage, they respond accordingly. And second, because the logic of marriage redefinition ultimately leads to the dissolution of marriage into nothing more than a social mess of consenting adult love of manifold sizes and shapes.

Those who defend — and live out — the truth about marriage should redouble their efforts to witness to the truth about marriage while there is still time to steer clear of that chaos. Here are six ways to do that.

I just chose one way of his six ways to quote in this post.

Here is way #3: make the case for marriage:

These religious-liberty protections are more likely to be respected if the underlying view about marriage is at least understood. Much of the opposition to Arizona’s recent religious-liberty legislation wasn’t directed at religious liberty per se but at misunderstood — sadly, at times intentionally misrepresented — concerns about being forced to celebrate same-sex relationships as marriages.

We will be most successful in protecting our rights to free speech, contract, association, and exercise of religion if we also make the reasonable case for marriage. Even if the Court or political powers force the redefinition of marriage, much of the future hinges on public opinion.

The key question is whether those who favor marriage redefinition will view — and thus treat — their dissenting fellow citizens as, in the words of Justice Scalia, “enemies of the human race,” or instead treat us as they do the pro-life movement. While liberal elites disagree with the pro-life position, they can at least understand it. And they can understand why a pro-life citizen holds the views she does and why government thus shouldn’t coerce citizens into performing or subsidizing abortions.

We therefore must do the work to make our fellow citizens at least understand why we believe what we do about marriage. Even if they continue steadfast in their convictions, they may at least see the reasonableness of ours. For too many of our neighbors, our beliefs about marriage are equated with the late Fred Phelps of Westboro Baptist infamy. If he’s the only voice they’ve heard on the issue, it’s hard to blame them. We must work harder so that they hear our voices.

All of us must be engaged in making the case for marriage. Roughly two years ago, Sherif Girgis, Robby George, and I finished working on the book that Alito cited, What Is Marriage? Man and Woman: A Defense. In that book we argued that there were two competing views of what marriage is that were in play in our national debates, and we made a philosophical argument that the conjugal view of marriage was correct, and the revisionist view false.

The conjugal view of marriage, we argued, has long informed the law — along with the literature, art, philosophy, religion, and social practice — of our civilization. So understood, marriage is a comprehensive union. It unites spouses at all levels of their being: hearts, minds, and bodies, where man and woman form a two-in-one-flesh union. It is based on the anthropological truth that men and women are distinct and complementary, on the biological fact that reproduction requires a man and a woman, and on the sociological reality that children benefit from having a mother and a father. As the act that unites spouses can also create new life, marriage is especially apt for procreation and family life. Uniting spouses in these all-encompassing ways, marriage calls for all-encompassing commitment: permanent and exclusive.

The state cares about marriage because of marriage’s connection with children and its ability to unite children with their mother and father. After all, whenever a baby is born, there is always a mother nearby: That is a fact of reproductive biology. The question for law and culture is whether a father will be involved in the life of that child and, if so, for how long. Marriage increases the odds that a man will be committed both to the children that he helps create and to the woman with whom he does so. Marriage, rightly understood, brings together the two halves of humanity (male and female) in a monogamous relationship. Husband and wife pledge to each other to be faithful by vows of permanence and exclusivity. Marriage provides children with a relationship with the man and the woman who made them.

The revisionist view, on the other hand, has informed certain marriage-policy changes of the past several decades and is embodied in much of Hollywood’s productions. On the revisionist understanding, marriage is essentially an emotional union, accompanied by any consensual sexual activity the partners may desire. Such romantic unions are seen as valuable while the emotion lasts. The revisionist view informs some male-female bonds, not just same-sex ones, as both involve intense emotional bonding, so both can (on this view) make a marriage.

But comprehensive union, we argue, is something only a man and woman can form. For this reason, enacting same-sex marriage would not expand the institution of marriage, but redefine it. Finishing what policies like “no-fault” divorce began, and thus entrenching them, it would finally replace the conjugal view with the revisionist emotion-based account. This would multiply the marriage revolution’s moral and cultural spoils, and make them harder than ever to recover.

Most Americans are unaware that there are two competing visions of marriage on offer in this debate, but my experience on dozens of college campuses during the past year suggests there is hope here. On almost every campus I visited, including such elite law schools as Stanford and NYU, students came up to me afterward to say that they had never heard a rational case for marriage. Christians would say that they always knew marriage was between a man and a woman, but never knew how to defend it as a policy and legal matter — that they knew what the Bible revealed and the church taught, but lacked a vocabulary for articulating what God had written on the heart. Now they could better explain how faith and reason went together; how theology and philosophy, the Bible and social science all pointed to the same truth.

Reassuring these students is crucially important. Simply preventing those who do affirm that marriage is the union of a man and a woman from internalizing doubt, from cowering in shame in the face of aggressive opposition, or ultimately from caving is essential.

So, too, is helping those who haven’t made up their minds see that this is a debate with competing reasonable positions. Some are genuinely on the fence, and we should do what we can to keep them from coming down on the wrong side. Indeed, my co-authors and I have received dozens of notes over the past year from people who decided to come down on the right side because of some aspect of our case for marriage.

While we may not be able to convert the committed advocates for same-sex marriage, we should seek to soften their resolve to eliminate us from polite society. Indeed, on campus after campus, students who identified as liberal would admit that this was the first time they had heard a rational case for marriage. They would tell me that they respected the argument — and frequently weren’t sure why it was wrong, even when they continued to insist that it was wrong. Winning over these students so that they will at least respect our religious-liberty rights is essential. We do that, in part, by explaining the reasons for our beliefs about marriage.

And yet there are naysayers who claim that rational arguments never convince anyone. There is something perverse in conservatives’ thinking that ideas have consequences but that good ideas can’t persuade. They can, if only we are willing to present them in a winsome manner. In the long run truth wins out.

It’s a long post, but if you are serious about doing something on this issue, then it’s worth a read. Anderson is one of the most articulate, prolific defenders of marriage operating today.