More than 500 evangelical leaders and pastors from every state in the country have signed a letter denouncing President Donald Trump’s executive order on immigration.

The letter, which appeared as a full-page ad in Wednesday’s Washington Post, points to the role that local churches have played in helping refugees resettle in the United States. The leaders used the Bible to emphasize that welcoming the refugee is a Christian duty.

“As Christians, we have a historic call expressed over two thousand years, to serve the suffering,” the letter states. “We cannot abandon this call now.”

But there’s a divide between the pulpit and the pew on this issue. Although this formidable group of conservative Christian pastors agree that caring for the stranger is the right thing to do, many rank and file evangelicals around the country are fearful about letting refugees into the United States.

So while the letter is addressed to Trump and Pence, the pastors also face the task of getting other American evangelicals on board.

Pool via Getty Images President Donald Trump speaks to the Major Cities Chiefs Association (MCCA) Winter Meeting on February 8, 2017 in Washington, DC.

The letter was organized by World Relief, the humanitarian arm of the National Association of Evangelicals. World Relief is one of the nine voluntary agencies that work with the federal government to help resettle refugees.

World Relief collected signatures from conservative evangelical leaders who don’t often speak out on political issues ― such as Tim and Kathy Keller, of New York’s Redeemer Presbyterian Church, and the Christian author Max Lucado.

“For some people, embracing refugees is a political issue,” evangelical author Lynne Hybels said in a statement about the letter she signed. “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.’”

Trump’s executive order temporarily banned refugees and immigrants from seven Muslim-majority countries from entering the United States. Refugees from the war-torn country of Syria were blocked indefinitely.

But the order has faced a number of legal challenges. Last week, a federal judge blocked it from being implemented nationwide. A panel of federal appeals judges is currently weighing the legality of that decision.

Kamil Krzaczynski / Reuters Syrian refugee Baraa Haj Khalaf (L) reacts as her mother Fattoum (C) cries and her father Khaled (R) looks on after arriving at O'Hare International Airport in Chicago, Illinois, U.S. February 7, 2017.

Religious leaders across the country, from a broad array of faiths and spiritual traditions, have denounced the order. Wednesday’s letter showed that prominent conservative leaders in the evangelical Christian tradition are willing to come out en masse to oppose Trump’s strategy on immigration and refugees.

However, the pastors’ sentiments may not reflect the opinions of all American evangelicals.

“It’s not a biblical command for the country to let everyone in who wants to come, that’s not a Bible issue,” Graham told HuffPost.

More broadly, many evangelicals have historically disapproved of the idea of America increasing the number of refugees it accepts into the country. According to statistics collected by the Pew Research Center in October 2016, 67 percent of white evangelical Christians think the U.S. does not have a responsibility to accept refugees from Syria. Another poll conducted in January showed that 64 percent of white evangelicals believe that the large number of refugees leaving countries like Iraq and Syria pose a “major threat.”

While Protestant pastors agree that Christians should care for refugees, many also say their congregants have fears about refugees coming to the United States, according to a 2016 survey by the Christian research firm LifeWay.

Richard J. Mouw, a professor at Fuller Theological Seminary who signed World Relief’s letter, said that he doesn’t often see value in adding his name to protest statements. But he saw this letter as a “teaching moment” for the evangelical community as a whole.

Making public statements and preaching about social concerns is not enough. It has to permeate what we read, how we watch TV, what we pray about. Richard J. Mouw

Mouw told The Huffington Post that he believes it's important to address the "teaching gap" between evangelical leaders and their congregants.

"Making public statements and preaching about social concerns is not enough. It has to permeate what we read, how we watch TV, what we pray about, where we reach out in friendship to people who are different from ourselves. The challenge is urgent right now," Mouw wrote in an email.

He suggested having church members meet in small groups to discuss the letter, or creating spaces where people can have honest conversations about why white evangelicals and evangelicals of color tend to approach these issues differently.

"Most of all: we need training in how genuinely to listen to each other in talking about how our faith--including our understanding of what the Bible teaches--relates to how we view the big issues being debated today in the public square," he wrote.

In 2016, three leaders from World Relief published a book that seeks to apply biblical principles to the refugee crisis and educate people about the United States’ refugee resettlement program.

Matthew Soerens, U.S. Director of Church Mobilization at World Relief and one of the co-authors of Seeking Refuge told The Huffington Post that his organization is doing “everything we can” to get this resource out to the evangelical community ― through Bible studies, Sunday School curricula, and sermon suggestions for pastors.

Soerens said that the negative political rhetoric around Syrian refugees, if taken at face value, may have clouded some evangelicals’ opinions about refugees from that country. He’s confident that personally getting to know a refugee can “rebut a lot of the stereotypes and misconceptions peddled by politicians or some media.”

“We’ve found that when people learn both the truth about how refugees are vetted and the remarkable history of safety in the refugee resettlement program, as well as are reminded what the Bible teaches on this topic, most evangelical Christians are very compassionate,” he told HuffPost in an email.

Scott Olson via Getty Images A supporter waits at O'Hare Airport for Syrian refugee Baraa Haj Khalaf and her family to arrive on a flight from Istanbul, Turkey at O'Hare Airport on February 7, 2017 in Chicago, Illinois.

Ed Stetzer, The Billy Graham Distinguished Endowed Chair for Church, Mission, and Evangelism at Wheaton College, told The Huffington Post he believes evangelicals’ fear about refugees can be cleared up with facts.

“Facts are our friends, here and always. The numbers show that this has been a safe program. When people see the actual numbers, and when they meet the refugees sponsored by many churches, they see the facts and can respond in faith rather than fear,” Stetzer wrote in an email.