It was organized by World Relief, a ministry that partners with churches to serve vulnerable people across the globe, which placed the letter in a full-page ad in The Washington Post.

The group is united against the president's DACA (Deferred Action for Childhood Arrivals program) deadline and is advocating for a more welcoming immigration and refugee policy.

"As Christian leaders, we have a commitment to caring for the vulnerable in our churches while also supporting just, compassionate and welcoming policies toward refugees and other immigrants," the letter reads.

"The Bible speaks clearly and repeatedly to God's love and concern for the vulnerable and also challenges us to think beyond our nationality, ethnicity or religion when loving our neighbor," it continues.

The letter comes one day after the president convened a meeting with national security leaders to discuss the problem of MS-13, a gang whose members are principally illegal immigrants from El Salvador.

He told the people he assembled for the meeting that if Congress can't get the job done on immigration then he welcomes a shutdown.

"If we don't get rid of these loopholes where killers are allowed to come into our country and continue to kill gang members and we're just talking about MS-13 ... I'd love to see a shutdown if we don't get this stuff taken care of," the president said.

Rev. Samuel Rodriguez, head of the National Hispanic Leadership Conference, signed the letter. He has advised President Trump and his team on immigration policy and also served as an evangelical adviser to President Barack Obama.

However, no other members of President Trump's evangelical advisory team signed the letter.

The Christian leaders also raise concerns about drop-in refugees allowed in the U.S. under this administration, along with the so-called "chain migration" policy President Trump says must end.

"God ordained the family as the cornerstone of society, and we believe that our country is stronger when our citizens can be quickly reunited with their close family members," the letter reads.

"We pray you will respect the unity of the family," it continues.

Thousands of faith leaders will convene in Washington Thursday for the National Prayer Breakfast.

Meanwhile, the House has passed a temporary spending bill that keeps the government running until the end of March, now the Senate will consider the measure.

Senate Majority Leader Mitch McConnell says once the government is funded, he'll work on addressing DACA before the president's deadline of March fifth.