They issued a warning in bold type, "We will not honor any decision by the Supreme Court which will force us to violate a clear biblical understanding of marriage as solely the union of one man and one woman."

They argued that traditional marriage "precedes civil government," and is "based not solely on religion but on the Natural Law, written on the human heart." (See defendmarriage.org.)

Religious leaders implored the Court "not to step outside of its legitimate authority and unleash religious persecution and discrimination against people of faith. We will be forced to choose between the state and our conscience."

These are chilling words. They underscore the gravity of the decision.

Dr. James Dobson, the noted radio talk show host, one of the organizers of Open Letter, told me in an interview, "We face the possibility -- the certainty -- that this 5,000-year-old institution is to be redefined and undermined in a way that will have devastating consequences for this country. Traditional marriage has been the foundation of every civilization in every country on earth since ancient times. Everything in the culture sits on that foundation.

"Our government, our way of life, the way we raise our children -- every dimension will be influenced by this decision. If we tamper with it, the entire superstructure can come down. The nation will never be the same."

Another key drafter of the declaration was Mathew Staver, Chairman of Liberty Counsel Action. He compared the issue to that of the Dred Scott decision of 1857 in which the Supreme Court "told Scott he was not entitled to full citizenship, because people believed that `blacks are inferior human beings.'" Abraham Lincoln "advocated disobedience to Dred Scott."

Similarly, Staver is calling for "resistance to a Supreme Court decision that could go the wrong way." For example he noted that when Massachusetts became the first state to legalize same-sex marriage, that Catholic Charities refused to place orphans in same-sex homes, so they stopped doing adoptions. "What they should have done, and now what we should do, is to say we are called on a mission, and that is the place orphans in homes with moms and dads."

This will not be easy. Melissa Klein, owner of Sweet Cakes by Melissa, refused to bake a cake for a lesbian couple, citing her faith. She was sued by Oregon's Bureau of Labor Industries, lost, and must pay a $135,000 fine. She closed the business. The Family Research Council created a GoFundMe account to help, and raised $100,000 in eight hours. However, GoFundMe pulled the plug on it, which prompted Franklin Graham to offer the help of Samaritan's Purse.

Phil Burress, President of Citizens for Community Values, the Family Policy Council in Ohio, signed the Open Letter because he believes marriage is a states' rights issue. "So far the score is 31 to 3 when people go to the polls to vote" in different states. Some 51 million people have voted for traditional marriage.

However, various courts have overturned 26 of those state ballots, "telling the people that their votes don't count," asserted Burress. "The rule of law means nothing to the judges who have turned into legislators." The Supreme Court is reviewing the only U.S. Appeals Court to uphold traditional marriage in four other states.

Even if the Court legalizes same-sex marriage, Burress thinks "This will backfire. It will be rejected eventually. The experiment will blow up in their face, as people realize they are losing religious liberty."

Staver recalled the ministry of a Lutheran pastor, Peter Muhlenberg, who preached a sermon in January, 1776 in Woodstock, Virginia on Ecclesiastes 3 which states, "There is a time for everything...a time for war and a time for peace." He then declared, "And this is a time of war," and took off his clerical robe to reveal his Colonel's uniform. He marched down the aisle as drums began to roll outside, and 162 men were enrolled in the first southern regiment of the American Revolution.

Will Americans respond in a similar way if the Supreme Court backs same-sex marriage?

I hope so.

Mike McManus is President of Marriage Savers and a syndicated columnist, writing Ethics & Religion weekly