WASHINGTON – Conservative Christians are not intimidated by the advances that same-sex marriage advocates have been making in the U.S.

In fact, they believe they're getting stronger and that now is not the time to give up.

"With every so-called defeat, more people come forward and say 'Enough is enough. We need to stand up for marriage,'" said Brian Brown, president of National Organization for Marriage, during a rally Sunday.

NOM just completed its "Summer for Marriage" bus tour and made its last stop in front of the U.S. Capitol. Brown visited 23 cities in 19 states proclaiming the message that marriage is a union between a man and a woman.

He was met with hundreds of protesters, many of whom attempted to shout him down and disrupt the NOM rallies.

"I will say this: Let us meet any form of hatred here today with love because we know where we come from, we know who we are and we know what this fight is about," he said Sunday in front of over a hundred supporters and dozens of protesters.

"It is about a profound love and respect for an institution that the government did not create; an institution that predates churches, governments ...; an institution that brings together the two great halves of humanity – male and female."

Brown approached the crowd on Sunday with the same language that he believes gay rights advocates have been misusing.

"I believe that this fight is the beginning of a new civil rights movement, and I don't say that in any shallow way," he said.

He explained to The Christian Post in an interview ahead of the rally that “a lot of African-American leaders … are tired of their struggle being hijacked by those who are attempting to use the civil rights movement to redefine marriage.”

Pushing back against comparisons between laws banning interracial marriage with ones that prohibit gays and lesbians from marrying, Brown contended, “Marriage is not based upon race. It's based upon the fact that there are men and women and men and women are brought together in marriage. So trying to compare same-sex marriage to overturning laws against interracial marriage is comparing apples to oranges.”

Brown said they are not fighting the marriage battle with Scripture, but with reason and the Constitution.

“Unaided reason alone tells us that marriage is the union of a man and a woman. We can understand by reason that marriage is that institution that brings men and women together and connects them with any children they may bear. No other relationship can do what marriage does. Our stand is based on the Constitution and is based on defending civil rights – our civil rights.”

The conservative and religious communities are fighting for the right to vote on the issue of same-sex marriage – rather than allowing legislature or the courts to rule on the issue. At the same time, they are also trying to defend their religious liberties.

If same-sex marriage was to win out in states across the entire country, Christians would begin to see lawsuits brought against them, warned Bishop Harry Jackson, a pastor from Beltsville, Md., who has been on the frontlines of the marriage debate in Washington.

The gay rights advocacy groups will not stop at marriage, he told The Christian Post.

Jackson likened them to "the bully in the playground."

"They're going to find some other way to take our lunch money," he said.

Some of those attacks will be aimed at a minister's sermon content.

"They'll say it's not right for us to preach our view of marriage because it's an assault against another group's civil rights and they'll equate it to the preaching of the KKK," he said. "It's very serious."

Also foreseeing the consequences, Brown pointed out that Christians will be accused of being bigots if language like the one seen in Judge Vaughn Walker's recent decision striking down California's Proposition 8 is put into law.

"Religious organizations are going to be punished if same-sex marriage stands in California and throughout the country. Why? Because we're going to be told that we are the equivalent of bigots and the law saying that has a tremendous powerful effect," Brown warned.

"When our children are taught in our schools that it's the same thing for Jimmy to grow up and marry Johnny as it is to marry Mary, and that you, the parents, are bigots for teaching them otherwise? There is a core civil right that has just been abridged."

Judge Walker ruled early this month that the state amendment defining marriage as between a man and a woman is unconstitutional. He wrote in his opinion that the amendment was passed by 52 percent of California voters out of fear, "unarticulated dislike," or moral disapproval for same-sex couples.

"The evidence at trial regarding the campaign to pass Proposition 8 uncloaks the most likely explanation for its passage: a desire to advance the belief that opposite-sex couples are morally superior to same-sex couples," Judge Walker wrote.

Traditional marriage supporters expect the California marriage case to reach the Supreme Court where they are confident they will win.

"Same-sex marriage advocates have attempted to steal the right of the people to vote in the name of civil rights. [But] you're stealing others' civil rights," Jackson commented.

"Runaway legislatures [and] overreaching judges have violated the spirit of the Constitution and betrayed the very heart of the American culture," he added. "It is not going to work. It is not going to stand."

Though same-sex marriage proponents are pushing the case that marriage is a fundamental right, Jackson argues otherwise.

"We discriminate in marriage," he noted. "We will not let brothers and sisters marry. We will not let old people and really young people marry. We will not allow people to marry under a lot of different circumstances. "

"Once you say this is [a foundational right], their arguments are fairly logical. If you deny that this is a foundational right, it's irrational from that point."

With no plans to step back from the marriage fight, Bishop Jackson ultimately believes that marriage is an institution that was founded by God and a treasure to preserve.

"I don't think in good conscience we can just let it go," he commented. "I have a hard time believing that Jesus would say 'Don't stand up for what the Word says.'"

“Marriage, in its traditional form, is one of our nation's greatest treasures. It's the first schoolhouse; it's the first church; it's the first place where values are imparted one generation to another.”