IN the past several years, American evangelicals, and I am one of them, have amassed greater political power than at any time in our history. But at what cost to our witness and the integrity of our message?

Recently, I took a few days to reread the war sermons delivered by influential evangelical ministers during the lead up to the Iraq war. That period, from the fall of 2002 through the spring of 2003, is not one I will remember fondly. Many of the most respected voices in American evangelical circles blessed the president's war plans, even when doing so required them to recast Christian doctrine.

Charles Stanley, pastor of the First Baptist Church of Atlanta, whose weekly sermons are seen by millions of television viewers, led the charge with particular fervor. "We should offer to serve the war effort in any way possible," said Mr. Stanley, a former president of the Southern Baptist Convention. "God battles with people who oppose him, who fight against him and his followers." In an article carried by the convention's Baptist Press news service, a missionary wrote that "American foreign policy and military might have opened an opportunity for the Gospel in the land of Abraham, Isaac and Jacob."

As if working from a slate of evangelical talking points, both Franklin Graham, the evangelist and son of Billy Graham, and Marvin Olasky, the editor of the conservative World magazine and a former advisor to President Bush on faith-based policy, echoed these sentiments, claiming that the American invasion of Iraq would create exciting new prospects for proselytizing Muslims. Tim LaHaye, the co-author of the hugely popular "Left Behind" series, spoke of Iraq as "a focal point of end-time events," whose special role in the earth's final days will become clear after invasion, conquest and reconstruction. For his part, Jerry Falwell boasted that "God is pro-war" in the title of an essay he wrote in 2004.

The war sermons rallied the evangelical congregations behind the invasion of Iraq. An astonishing 87 percent of all white evangelical Christians in the United States supported the president's decision in April 2003. Recent polls indicate that 68 percent of white evangelicals continue to support the war. But what surprised me, looking at these sermons nearly three years later, was how little attention they paid to actual Christian moral doctrine. Some tried to square the American invasion with Christian "just war" theory, but such efforts could never quite reckon with the criterion that force must only be used as a last resort. As a result, many ministers dismissed the theory as no longer relevant.

Some preachers tried to link Saddam Hussein with wicked King Nebuchadnezzar of Biblical fame, but these arguments depended on esoteric interpretations of the Old Testament book of II Kings and could not easily be reduced to the kinds of catchy phrases that are projected onto video screens in vast evangelical churches. The single common theme among the war sermons appeared to be this: our president is a real brother in Christ, and because he has discerned that God's will is for our nation to be at war against Iraq, we shall gloriously comply.

Such sentiments are a far cry from those expressed in the Lausanne Covenant of 1974. More than 2,300 evangelical leaders from 150 countries signed that statement, the most significant milestone in the movement's history. Convened by Billy Graham and led by John Stott, the revered Anglican evangelical priest and writer, the signatories affirmed the global character of the church of Jesus Christ and the belief that "the church is the community of God's people rather than an institution, and must not be identified with any particular culture, social or political system, or human ideology."

On this page, David Brooks correctly noted that if evangelicals elected a pope, it would most likely be Mr. Stott, who is the author of more than 40 books on evangelical theology and Christian devotion. Unlike the Pope John Paul II, who said that invading Iraq would violate Catholic moral teaching and threaten "the fate of humanity," or even Pope Benedict XVI, who has said there were "not sufficient reasons to unleash a war against Iraq," Mr. Stott did not speak publicly on the war. But in a recent interview, he shared with me his abiding concerns.

"Privately, in the days preceding the invasion, I had hoped that no action would be taken without United Nations authorization," he told me. "I believed then and now that the American and British governments erred in proceeding without United Nations approval." Reverend Stott referred me to "War and Rumors of War, " a chapter from his 1999 book, "New Issues Facing Christians Today," as the best account of his position. In that essay he wrote that the Christian community's primary mission must be "to hunger for righteousness, to pursue peace, to forbear revenge, to love enemies, in other words, to be marked by the cross."

What will it take for evangelicals in the United States to recognize our mistaken loyalty? We have increasingly isolated ourselves from the shared faith of the global Church, and there is no denying that our Faustian bargain for access and power has undermined the credibility of our moral and evangelistic witness in the world. The Hebrew prophets might call us to repentance, but repentance is a tough demand for a people utterly convinced of their righteousness.

[Charles Marsh, a professor of religion at the University of Virginia, is the author of "The Beloved Community: How Faith Shapes Social Justice, from the Civil Rights Movement to Today."]