All of a sudden, they are bigots and haters — they who stood tall against discrimination, who marched and sat in, who knew better than most the pain of being told they were less than others.

They are black men, successful ministers, leaders of their community. But with Maryland poised to become the eighth state in the nation to legalize same-sex marriage, they hear people — politicians, activists, even members of their own congregations — telling them they are on the wrong side of history, and that’s not where they usually live.

Sometimes, the pastors say, the name-calling and the anger sting.

Nathaniel Thomas spent decades as an administrator in Howard University’s student affairs office, counseling young people not only about their course work but also about their personal quests for justice. He came to the ministry at the dawn of middle age, eager to help people, and especially fellow black men, discover in the word of God a path out of despair.

Over the past couple of years, as Thomas and dozens of other black clergymen in Prince George’s County have stood on the front line of the campaign against same-sex marriage, he has come to see the revolution at hand — in his view, a rebellion against religion and tradition — as an assault on the sustainability of the black family.

Which is why Thomas and his friend Reynold Carr, director of the Prince George’s Baptist Association, are gearing up for the next battle, a statewide ballot referendum in November to challenge the legalization of same-sex marriage, which the state House of Delegates approved last Friday. The state Senate passed a measure Thursday evening; Gov. Martin O’Malley (D) said he will sign the bill. The pastors are not predicting victory in a referendum, but they think they stand a better chance among voters than politicians.

“This is a cultural war, a cultural shift, and those who are in rebellion have decided to portray us as bigots and prejudiced,” says Thomas, pastor of Forestville New Redeemer Baptist Church, a trim, pale-brick building across from a storage facility on a dead-end road just inside the Beltway near Pennsylvania Avenue.

He knows that some gay activists are incredulous that black ministers could oppose a civil rights initiative. “ ‘How dare a black preacher take this position,’ they say, ‘because you’ve felt this pain,’ and I have,” he says. Over the decades, he has marched for voting and housing rights and fought for equal protection for blacks.

But Thomas and the 77 other Baptist ministers in the association do not see same-sex marriage as a civil rights matter. Rather, they say, it is a question of Scripture, of whether a country based on Judeo-Christian principles will honor what’s written in Romans or decide to make secular decisions about what’s right. In Maryland, as in California and New York, opinion polls have shown that although a majority of white voters support recognition of same-sex marriage, a majority of blacks oppose it, often on religious grounds.

Thomas, 61, says a couple of young women in his church told him that maybe it’s not so bad to allow two women to join together because, in many cases, men are not in the home.

His booming voice softens: “We do have a flat tire in our community when it comes to marriage and men in the household. But do we flatten the other three tires to move forward, or do we work on fixing the flat tire? Do we give up on the lack of strong black men leading our households and justify another change in our social structure?”

Thomas has seen sermons by a few fellow preachers railing against homosexuals, calling their behavior “disgusting” and egging on congregants who shout catcalls at the mention of gay sex.

Those are errant cries, he says, that fail to honor the Christian obligation to embrace those who commit acts the Bible calls sinful.

Not long ago, Thomas says, a young gay man came to him and said, “Look, I can’t help being how I am.” The minister embraced the man.

“We are all sinners,” Thomas says. “Christ never turned anyone away. People come to us all the time with issues, some with a stealing demon, some with urges and desires. But love doesn’t mean you go along to get along. I counsel them by showing them God’s word; some receive the word, and some reject it.”

Thomas’s friend Carr, who spent 22 years leading Kent Baptist Church in Landover before taking over the Pastors Association, steps into his office in a modest house on Princess Garden Parkway in Lanham and retrieves a black leather-bound Bible.

“Sin is rebellion against God and his standards,” Carr, 67, says in the soft, lilting island tones of his native Trinidad. He opens the book to Romans 1:27.

Thomas, a mound of a man who is more given to florid language, takes the book and starts reading about “men with men working that which is unseemly,” but he does not stop at admonitions against homosexuality. Read on, he says, and he does, into a litany of other “unrighteous” behaviors — “fornication, wickedness, covetousness.”

“So it is all of us who are listed here — not just homosexuals, but every one of us,” Thomas says. “We all got some stuff.”

The battle over same-sex marriage, for Thomas and Carr, is not so much about homosexuality as about a growing belief that biblical principles should not be the basis for governing.

“Take the word ‘marriage’ out of this bill, and we’re pretty much in agreement,” Thomas says. “Everyone should have full legal rights and would have them with civil unions. You wouldn’t see me down there protesting against civil unions. The state is the state, and the church is the church. I understand that. But put the word ‘marriage’ in there, and now you’re redefining something that is in the Bible and in our principles as one man and one woman. Why do you need to use a biblical word in a civil situation?”

Thomas sees the bill as a blueprint the state will use to require churches that run day-care centers or schools to teach something they don’t believe in. “Now, if the marriage law protected churches from lawsuits by people who might say, ‘You discriminated against me because you wouldn’t marry me,’ that would begin to put folks at ease,” he says.

Maryland’s marriage bill would prohibit any lawsuit against religious entities or clergy based on a refusal to perform a wedding.

O’Malley and some other Democratic governors, such as New York’s Andrew M. Cuomo, have pressed the issue, in part because they see public opinion moving swiftly in the direction of same-sex marriage and because they believe it is this generation’s civil rights issue.

But where the governors’ supporters see a pleasing blend of principle and political savvy, the pastors see a toxic mix of cynicism and antagonism toward religion.

Over and over, the ministers return to the image that some supporters of same-sex marriage have painted of the church as hater. “There is not one of us who doesn’t have persons in our family with that lifestyle,” Thomas says. “And I tell them, ‘You are still mine.’ ” His voice cracks; he halts for a moment. “You are flesh of my flesh, blood of my blood. No, I will not discriminate against him. We are a people of mercy. But the state may not tell me that I must sanction his behavior, just as I may not sanction behavior of the adulterer or the liar.”

The next battle, the marker the pastors intend to throw down in a statewide vote on same-sex marriage, will be over whether Democratic politicians can still take for granted the votes of black churchgoers and others in the community who stand in opposition.

“It’s really believers against nonbelievers. If it goes the other way, well, I’m a citizen and a taxpayer, and I have to live by what the people decide. People on the street say, ‘Y’all church, y’all reverends are wrong because you’re trying to stop people’s rights.’ No, the only thing we’re asking is don’t use the word marriage — one word.”