Lawmakers in Illinois are considering a bill to redefine marriage. This comes a little over a year after the state created civil unions for those in same-sex relationships by passing the Religious Freedom Protection and Civil Union Act. Shortly thereafter, Catholic Charities was forced out of foster care and adoption services in Illinois.

This new bill, disingenuously titled the Religious Freedom and Marriage Fairness Act, neither protects religious liberty nor treats marriage fairly. Every marriage policy draws lines, leaving out some types of relationships. But fairness forbids arbitrary line-drawing. Determining which lines are arbitrary requires us to answer two questions:

  1. What is marriage?
  2. Why does it matter for policy?

Reflecting on these questions reveals why there’s nothing “fair” about redefining marriage to eliminate the norm of sexual complementarity. Indeed, there are many good reasons why citizens in 41 states have said over and over that marriage is between a man and a woman. Marriage exists to bring a man and a woman together as husband and wife to be father and mother to any children their union produces. And as ample social science has shown, children tend to do best when reared by their mother and father.

Government recognizes marriage because it is an institution that benefits the public good.

Marriage is society’s least restrictive means to ensure the well-being of future citizens. State recognition of marriage protects children by incentivizing adults to commit permanently and exclusively to each other and their children.

While respecting everyone’s liberty, government rightly recognizes, protects, and promotes marriage as the ideal institution for procreative love, childbearing, and child-rearing.

The truth about marriage is not a sectarian issue. Chicago’s Archbishop Francis Cardinal George says as much: “[T]he nature of marriage is not a religious question. Marriage comes to us from nature.” He adds:

[T]he State protects marriage because it is essential to family and to the common good of society. But neither Church nor State invented marriage, and neither can change its nature.

Nature and Nature’s God, to use the expression in the Declaration of Independence of our country, give the human species two mutually complementary sexes, able to transmit life through what the law has hitherto recognized as a marital union.

And he highlights what is at stake in redefining marriage:

What is certainly at stake is the natural relationship between parents and children. Children, even if they are loved and raised by those who are not their biological parents, want to know who their parents are, who are their natural family…. No honest “study” has disproved what we all know. Stable marriage between a husband and wife has safeguarded their children, surrounding them with familial love and creating the secure foundation for human flourishing. This natural desire, already weakened in a seemingly more and more promiscuous society, will no longer be privileged in civil law. It will be no more “normal” than any other “family” arrangement. If the nature of marriage is destroyed in civil law, the natural family goes with it.

Cardinal George observes that “a proposal to change this truth about marriage in civil law is less a threat to religion than it is an affront to human reason and the common good of society.” Yet it is still a threat to religion, as the bill fails to protect religious liberty. The Catholic bishop of Springfield, Illinois, Thomas John Paprocki, explains:

The pending bill is not only a dangerous social experiment about marriage. It is also a lethal attack upon religious liberty. This so-called “religious freedom” would not stop the state from obligating the Knights of Columbus to make their halls available for same-sex “weddings.” It would not stop the state from requiring Catholic grade schools to hire teachers who are legally “married” to someone of the same sex. This bill would not protect Catholic hospitals, charities, or colleges, which exclude those so “married” from senior leadership positions. Nor would it protect me, the Bishop of Springfield, if I refused to employ someone in a same-sex “marriage” who applied to the Diocese for a position meant to serve my ministry as your bishop. This “religious freedom” law does nothing at all to protect the consciences of people in business, or who work for the government. We saw the harmful consequences of deceptive titles all too painfully last year when the so-called “Religious Freedom Protection and Civil Union Act” forced Catholic Charities out of foster care and adoption services in Illinois.

These threats do not raise a question about drafting a better law, one with more extensive conscience protections. There is no possible way—none whatsoever—for those who believe that marriage is exclusively the union of husband and wife to avoid legal penalties and harsh discriminatory treatment if the bill becomes law. Why should we expect it be otherwise? After all, we would be people who, according to the thinking behind the bill, hold onto an “unfair” view of marriage. The state would have equated our view with bigotry—which it uses the law to marginalize in every way short of criminal punishment.

As my Heritage Foundation colleague Tom Messner has documented again, and again, and again, redefining marriage has already been—and will continue to be—a nightmare for religious liberty.

To learn more about what marriage is, why it matters for policy, and why redefining marriage is unnecessary, unreasonable, and contrary to the common good, come to The Heritage Foundation’s lunchtime presentation next Tuesday, January 8, where my co-authors Sherif Girgis, Robert P. George, and I will discuss our new book What Is Marriage? Man and Woman: A Defense.