Faithful America, the activist organization associated with mainline Protestantism, has issued what it calls its “most important list of top Christian-nationalist False Prophets ever.”

What is Christian nationalism?

After hearing the refrain about the United States as a Christian nation far too often, I’ve come up with my own definition. Christian nationalists believe at least two of the following:

First, that the United States was founded as a Christian nation. Second, that the United States is now a Christian nation. Finally, that the United States should be a Christian nation.

All three propositions are demonstrably false — and dangerous. More important, these notions are destructive not only to democracy but also to the integrity of the faith.

The United States was emphatically not founded as a Christian nation. That’s the point of the First Amendment, America’s best idea: “Congress shall make no law respecting the establishment of religion or prohibiting the free exercise thereof.” The founders wanted to disentangle church and state, an alliance that had caused all manner of unrest and misery in Europe and England.

“Half the wars of Europe, half the troubles that have vexed European states,” James Bryce observed in 1893, “have arisen from theological differences or from the rival claims of church and state. This whole vast chapter of debate and strife has remained virtually unopened in the United States.”

Nor were the founders Christians, let alone evangelical Christians, as some Christian nationalists have argued. Figures like Benjamin Franklin, George Washington, Thomas Jefferson, John Adams and others would be laughed out of congregations now advocating Christian nationalism if they applied for membership in those churches.

No, the United States is not a Christian nation. At various points in our history, Christian zealots have sought to amend the Constitution to designate the United States as Christian.

The most famous example took place during the Civil War. In response to the Confederacy having declared itself a Christian nation in its constitution, an organizationcalled the National Reform Association drafted a constitutional amendment with a similar declaration and presented it to Abraham Lincoln.

The president wisely demurred. Happily, nothing came of the initiative, although the National Reform Association is still around and still pressing the matter.

Another attempt to declare the United States a Christian nation took place in the 1960s in response to Supreme Court decisions invalidating mandatory Bible reading and prescribed prayer in public schools. This initiative had the support of clergy and some powerful politicians, notably Everett Dirksen, U.S. senator from Illinois and minority leader. “Hell, I sound like Billy Graham,” Dirksen said. “I’m positively evangelical about this.”

Once again, this initiative faltered as citizens began to ask who would be composing the prayers that schoolchildren would be required to pray. And it’s also worth noting, as the late Mark O. Hatfield, U.S. senator from Oregon and a lifelong Baptist, pointed out, nothing whatsoever prohibits students from praying. The senator, in a speech on the Senate floor, confessed that he had prayed frequently in public schools, especially prior to math tests.

The reference to Billy Graham, the most influential evangelical of the 20th century, brings us back around to Faithful America’s catalog of false prophets. Graham’s son, Franklin, appears on this rogues list, having ignored his father’s wise words back in 1981.

“I don’t want to see religious bigotry in any form,” the elder Graham said in the early years of the Religious Right. “It would disturb me if there was a wedding between the religious fundamentalists and the political right. The hard right has no interest in religion except to manipulate it.”

Other names on Faithful America’s list include Leonard Leo, who with the connivance of Mitch McConnell has rendered the Supreme Court an enemy of the First Amendment, and Tony Perkins of the Family Research Council, a man with a history of entanglements with the Ku Klux Klan.

Al Mohler, president of Southern Baptist Theological Seminary, makes the cut, along with Samuel Alito, Ralph Reed and Mark Robinson, currently the Republican nominee for governor of North Carolina.

Christian nationalism is a very bad idea, both for democracy and for the faith itself. The First Amendment and the separation of church and state has ensured a vibrant religious marketplace and spared the nation from religious acrimony.

As Justice Sandra Day O’Connor wrote in her final opinion of church-state matters, “Those who would renegotiate the boundaries between church and state must answer a difficult question: Why would we trade a system that has served us so well for one that has served others so poorly.”

Randall Balmer, a professor at Dartmouth College, is the author of “Solemn Reverence: The Separation of Church and State in American Life.”