Author Ann Voskamp, left, stands outside the National Prayer Breakfast with a sign saying “We Welcome Refugees.” (Courtesy of Sarah Melnyk, Church World Service)

In a highly unusual move, several conservative evangelical leaders took out a full-page advertisement in Wednesday’s Washington Post to denounce President Trump’s executive order temporarily banning refugees, saying they are “deeply concerned.” The ad includes the signatures of evangelicals considered to be more conservative and represent large churches and institutions, including New York City Pastor Tim Keller and his wife, Kathy Keller, Southern Baptists Ed Stetzer and Daniel Akin and popular author Max Lucado.

The ad shows how the issue of refugees, which was once not considered divisive in evangelical circles, has become polarizing in recent years. The evangelical ministry World Relief, which is behind the ad that lists 100 evangelical leaders, said that more than 500 evangelical pastors and ministry leaders have added their signatures to the letter that will be delivered to Trump.

Last month, Trump signed an executive order that temporarily bars travelers from seven Muslim-majority nations, reduces the number of refugees the United States will admit and bars Syrian refugees indefinitely. A federal appeals court is considering the measure.

Trump said in an interview with the Christian Broadcasting Network that persecuted Christians would be given priority, an issue the leaders respond to in their ad.

“As leaders, we welcome the concern expressed for religious minorities, including persecuted Christians,” the ad states. “Followers of Christ face horrific persecution and even genocide in certain parts of the world. While we are eager to welcome persecuted Christians, we also welcome vulnerable Muslims and people of other faiths or no faith at all. This executive order dramatically reduces the overall number of refugees allowed this year, robbing families of hope and a future. And it could well cost them their lives.”

Several evangelical leaders have backed Trump’s executive order, including evangelist Franklin Graham, Liberty University President Jerry Falwell Jr. and Southern Baptist Pastor Ronnie Floyd. But Wednesday’s list of leaders included some who rarely get involved in political debates.

Other high-profile names included popular author Ann Voskamp, Bill and Lynne Hybels of Willow Creek Community Church and Leith Anderson, president of the National Association of Evangelicals. Voskamp traveled from her family’s pig farm in Canada to join about 200 other people last week to pray for refugees outside the Washington hotel where Trump was attending the National Prayer Breakfast.

Several of these leaders have tried to balance what they see as a need for both security and compassion. A 2016 Southern Baptist Convention resolution urged churches and families to welcome refugees while also calling on the government to “implement the strictest security measures possible” in screening them.

Evangelicals have been involved in ministry to refugees for decades, said Stetzer, who holds the Billy Graham Distinguished Chair at Wheaton College.

“This is not the usual list of left-leaning, social justice-oriented, religious leaders,” he said in an email. “This is a surprising list of prominent evangelicals who care enough about this issue to use their leadership platform to speak out, even when many evangelicals have deep fears and concerns about refugees entering this country.

Of religious groups polled by the Pew Research Center in October, evangelicals were the most likely to say the United States is not responsible for accepting Syrian refugees.

“We live in a dangerous world and affirm the crucial role of government in protecting us from harm and in setting the terms on refugee admissions,” the ad states. “However, compassion and security can coexist, as they have for decades. For the persecuted and suffering, every day matters; every delay is a crushing blow to hope.”

The question of whether to welcome refugees to the United States has only recently become politically controversial among evangelicals. When Matthew Soerens of the evangelical ministry World Relief co-wrote the book “Welcoming the Stranger” in 2009, Soerens said it barely touched on refugees because the idea was not seen as controversial.

Soerens said he has worked with more than 1,000 churches in the past two years and has not had one church back out of its ministry to refugees. He noted a surge in interest from some evangelicals in helping refugees, though he also says that in areas where refugees are not resettled people have “less personal experience with refugees to rebut the misconceptions they are hearing from some politicians.”

Lynne Hybels said in a statement that she has met refugees in Jordan, Lebanon, Iraq, Congo and in Illinois and Michigan.

“For some people, embracing refugees is a political issue,” she said in a statement. “For me, as a Christian, speaking up for and caring for refugees is more an act of worship and obedience to a God whose Kingdom is global and whose ‘mercies are new every morning.’”

The letter was joined by evangelical leaders who are immigrants, including Eugene Cho, a pastor in Seattle, and Gabriel Salguero, president of the National Latino Evangelical Coalition.

“My hope is that this will not be seen as a controversial position and that as evangelicals our allegiance would not be to partisanship but to our gospel convictions,” Salguero said in an email. “I fear that U.S. evangelicalism may be hyper-partisanized in a way that silences our public witness on key issues.”

The evangelical leaders join a long list of Catholic leaders who have condemned the executive order. Last week, Princeton University professor Robert P. George, a Catholic who is respected by evangelicals and was chair of the U.S. Commission on International Religious Freedom, denounced the executive order in First Things magazine.

“There are many things in our government that are ‘broken,’ but our refugee vetting system isn’t one of them,” George said. “We needn’t, and therefore we shouldn’t, shut out refugees who are fleeing terrorism in places such as Syria and Iraq, even temporarily. Because it isn’t necessary to do it, it is, in my opinion, necessary not to do it.”

This piece has been updated.