Anne Arundel County Del. Robert A. Costa will never get mistaken for a liberal. The Republican firefighter from Deale is a proud member of the National Rifle Association and aU.S. Army veteran who sports a 78 percent lifetime rating from the conservative-leaning Maryland Business for Responsive Government.

But on the matter of same-sex marriage, Mr. Costa was the first, and so far, only, House member from his political party to cast a vote in favor, sending the legislation to the House floor this week on a 25-18 dual committee vote. He does not approve of same-sex marriage, he explained, but he also opposes government deciding how two people should live, a matter that should be "between an individual and God."

To that, we can only say, amen. As the great privacy advocate and Supreme Court Justice Louis Brandeis once observed, the right most valued by civilized people is the right to be let alone. Maryland's problematic requirement of marriage, that it be granted to couples of opposing gender only, is an unnecessary infringement on the rights of gay and lesbian couples, particularly those raising children.

The legislation now pending in the House of Delegates is titled the "Civil Marriage Protection Act" for good reason. Much of the measure is devoted to making clear that no religious organization of any doctrine is required to accommodate same-sex marriages. Civil marriage refers to a marriage performed or recognized by a government official. That is all that is at stake in the debate.

But it is a substantial matter. Without marriage, same-sex couples in committed relationships are denied a raft of legal benefits. One survey estimated there are no fewer than 1,138 federal laws that grant rights and privileges to married heterosexual couples that are not provided to same-sex couples. They include matters related to health care decisions, real estate transfer taxes, inheritance taxes, visitation rights at nursing homes and on and on.

During a recent hearing in Annapolis, numerous parents testified about the many unnecessary hardships they had to endure because of the current prohibition. Here were families practicing the ideal of two committed parents devoted to their children, but state law was denying them the rights and benefits they needed — and deserved — to ensure the best possible outcome for the kids.

Certainly, there are religions that preach against same-sex marriage. The beauty of the legislation is that it forces such marriage on no one — not any couple and not any church. It merely leaves open the possibility for those who seek it.

In this, the measure is really little different from civil laws that permit contraception, consumption of alcohol or eating bacon, all of which are banned by certain faiths. It was not that long ago that people of one race were sometimes prohibited from marrying those of another. Such anti-miscegenation laws remained in force in this country until the mid-1960s.

Rarely have lawmakers in Annapolis been given an opportunity to cast such an important vote in favor of equal rights. Yet the House vote — expected to take place this week — is considered too close to call, with a handful of fence-sitting delegates left to decide its fate.

Social change rarely comes easily, but make no mistake, the legalization of same-sex marriage is inevitable. It is the direction in which this country is moving and the pace of that change is accelerating. Recently, Washington state approved it, joining the handful of states where same-sex marriage is permitted. The legislature in New Jersey will likely do the same. Voting the bill down this year does not mean the matter will go away. Lawmakers will confront the issue year after year until it is passed — and, ultimately, decided by the voters in a referendum.

In the meantime, same-sex couples in Maryland are making lasting commitments to each other. They are raising children together, and in many cases, they are getting married in other jurisdictions, including neighboringWashington, D.C.Those unions are already recognized as legal in Maryland — or at least they should be under an opinion issued two years ago by Maryland Attorney GeneralDouglas F. Gansler. While the Court of Appeals has yet to weigh in on the matter, Mr. Gansler believes the court will ultimately respect the laws of other states.

Given that the state Senate is on record in support of marriage equality, that leaves it to the men and women of the House to do the right thing and make Maryland the eighth state to permit same-sex marriage. To do otherwise, as Delegate Costa wisely pointed out, is to allow government to intrude where it ought not go. It is a matter of fairness, of equal rights, and social justice to ensure same-sex couples are not treated as second-class citizens.