Recently, I traveled to Washington, D.C., as a delegate for Clergy for Fairness, an interfaith group working nationally and locally to oppose discrimination and promote religious liberty.

More than 30 religious leaders from 10 states gathered on Capitol Hill to speak out against proposed legislation that would amend the U.S. Constitution to restrict marriage to heterosexual couples only. Because my faith tradition affirms marriage equality, both the moral and legal equality of marriage partners and the freedom of same-sex couples to marry on the same basis as different-sex couples, I’m committed to defeat any legislation that would write discrimination into law or infringe unnecessarily upon the free exercise of religion.

Defining marriage is not the state’s business. Each religious tradition should be free to decide, based on its own teachings, whether to recognize and bless the union of any couple, including the unions of same-sex couples. Moreover, it is not the federal government’s role to prefer one religious definition of marriage or impose that definition on all by codifying this preference into the Constitution.

By so doing, the government would also be offering some American families access to more than 1,000 federal benefits, such as health care, hospital visitation and family medical leave, while denying equal access to other American families. That’s unfair and wrong.

The so-called Federal Marriage Protection amendment is big trouble. For the first time in U.S. history, a constitutional amendment would be used to restrict, not expand, the rights of an entire group of citizens. Moreover, it’s not difficult to recognize that this amendment is a crass, politically motivated attempt in an election year to whip up voters by reinforcing prejudice against a stigmatized minority group.

Finally, this legislation tries to prematurely “settle” an important moral debate now under way within diverse faith traditions. It represents a sledgehammer approach to resolving hotly contested social issues. The Constitution should not be misused this way.

My defense of marriage equality is rooted not only in constitutional principles, but even more in the core Christian values of love and justice. The freedom to love and be loved defines what it means to be human. Marriage is a primary way many people choose to exercise this precious freedom, by entering into a committed covenantal relationship with the person they identify as their closest intimate and next of kin.

To deny this freedom to love and, yes, marry the person of one’s choosing is dehumanizing, oppressive, and, I would add, sinful. Denying this freedom to same-sex couples is also sacrilegious, given the long-standing religious insight that wherever there is covenantal love, there is God.

From a justice perspective, defending the right of same-sex couples to marry, both civilly and religiously, is a way to honor the humanity of gay and lesbian persons. In this regard, it is important to note how various groups in U.S. history have been denied the freedom to marry, including slaves and, as recently as the mid-1970s, interracial couples.

In the 1980s, the U.S. Supreme Court declared that marriage is such a fundamental human right that not even prisoners on death row should be denied this freedom, even if they would not be able to “consummate” their marriages. In 1999, the Vermont Supreme Court, in ruling in favor of marriage equality for same-sex couples, concluded, “When all is said and done, this is about our common humanity.” In 2003, the Massachusetts Supreme Judicial Court in its Goodrich decision said much the same thing. Granting the freedom to marry to same-sex couples may be a change in practice, the court said, but it is not a change in values.

In Christian perspective, marriage serves three good purposes: intimate bonding between two persons, the sharing of economic resources, and the nurturing of children. Same-sex couples can and do fulfill these three purposes. In recognition of this fact, the United Church of Christ has adopted a resolution in favor of marriage equality and affirmed that “all people have the right to lead lives that express love, justice, mutuality, [and] commitment.” This church also has urged people “to work against legislation, including constitutional amendments, which [would deny] civil marriage rights to couples based on gender.” Why?

First, because it’s unjust, unloving and wrong to deny same-sex couples and their families legal recognition (and religious blessing). Second, because the gender of the persons in intimate relationship is irrelevant. It’s irrelevant morally. It’s irrelevant spiritually. And it should be irrelevant legally. What matters is not the gender configuration, but rather the moral quality of their relationship.

As a clergyperson, I’ve performed weddings for heterosexual couples, and I’ve officiated at services for same-sex couples. I grant you that these couples may have looked different, but they were engaging in exactly the same practice: making sacred promises to love and support each another, in good times and in bad, and seeking their community’s blessing and ongoing support to journey together on this risky, yet life-enhancing pathway.

In a pluralistic church and society, the challenge before us is this: How do we provide the respect and material security needed to support strong, vibrant families, some of which are gay and lesbian families?

Discrimination does not, cannot and will never protect or enhance the institution of marriage. Only justice and equality under the law can truly protect marriage, demonstrate genuine respect for our common humanity and keep all our families safe and strong.

Marvin M. Ellison is Willard S. Bass Professor of Christian Ethics at Bangor Theological Seminary. An ordained minister, he is author of “Same-Sex Marriage? A Christian Ethical Analysis.”