Hilda Ramirez never steps foot outside St. Andrew's Presbyterian Church. When her 11-year-old son leaves for school, she holds her breath, praying that he will return. When sirens wail on the streets outside, her heart stops.

For much of the past two years, the Austin church has provided sanctuary for Ramirez, a 30-year-old immigrant who came to the U.S. illegally after fleeing violence in Guatemala.

She and her son, Ivan, sleep on bunk beds in a room in the east wing of the house of worship, where church members have been trained to form a human barrier should immigration agents show up.

"What else could you do?" said Pastor Jim Rigby, who never hesitated to offer St. Andrew's as refuge. "This is as foundational as anything there is. The core message of the Bible is not to mistreat immigrants and sojourners."

Rigby, whose church is one of about two dozen in the Austin Sanctuary Network, and among an estimated 800 across the country offering protection to immigrants at risk of being deported, is part of a growing chorus of Christian leaders stepping up to advocate for immigrants.

DiNARDO, OTHER CATHOLIC LEADERS: 'We need to help the Dreamers now'

The U.S. Conference of Catholic Bishops is staging a national call-in and a day of action this week to pressure members of Congress to pass legislation protecting "Dreamers," immigrants brought to the country illegally as children. Prominent evangelical leaders, including Russell Moore, leader of the Southern Baptist Convention's Ethics and Religious Liberty Commission, have issued open letters in support of the approximately 700,000 young immigrants shielded from deportation through the federal Deferred Action for Childhood Arrivals (DACA).

Others, such as Pastor Sam Rodriguez, who led a prayer at Donald Trump's inauguration, are directly lobbying lawmakers on behalf of DACA recipients and against mass deportation.

'Compelled by scripture'

The current climate of immigration raids, the increased threat of detention and deportation and the looming March 5 deadline for DACA has pushed religious leaders to take a more active role in the political debate.

It is an intensely personal issue in many U.S. churches, where immigrants fill the pews, serve as priests and deacons, attend Sunday school, file into parochial classrooms and aspire to be pastors. They are, said Rodriguez, "the future of American Christianity."

"As goes the immigrant community," he said, "so goes Christianity in America."

Nearly one-third of U.S. Catholics are foreign-born; another 15 percent have parents who are immigrants. About 40 percent of Eastern Orthodox Christians were born outside the country, as are a growing number of worshippers in both evangelical and mainline Protestant denominations, according the Pew Research Center. At the same time, the number of Americans with no religious affiliation has grown from 6 percent in 1992 to 22 percent in 2014, a Pew survey found. The decline is particularly notable among white Protestants.

If a fix for Dreamers, who number about 1.8 million including DACA recipients, is not found, the resulting deportations would reverberate in churches across the country.

About 124,000 DACA recipients live in Texas, including an estimated 80,000 in the Houston area. The metro area is home to nearly 600,000 immigrants who are in the country illegally, the third-largest concentration in the country.

"There would be many churches ripped apart, with vital members of the congregation and families ripped apart," Moore said. "It would be a tragedy."

For Moore and other faith leaders, the need to advocate for immigrants is also a pastoral and Biblical imperative, an instruction clearly stated in Matthew 25: "For I was hungry and you gave me something to eat, I was thirsty and you gave me something to drink, I was a stranger and you invited me in."

"It is impossible to be a Christian leader and not to address issues of Biblical justice," said Rodriguez, president of the National Hispanic Christian Leadership Conference. "We are compelled by scripture."

Trump ordered an end to DACA in September, giving lawmakers six months to come up with a replacement. A federal district judge in San Francisco has temporarily blocked Trump's effort to shut down the Obama-era program while a series of lawsuits proceed. The Department of Justice appealed the ruling directly to the Supreme Court, which announced Monday that it will not hear the case, leaving the matter to a federal appeals court to decide.

In mid-February, the Senate held a weeklong open immigration debate but failed to get the 60 votes needed to consider bipartisan immigration proposals.

'Welcoming the stranger'

Opponents of DACA and those pushing stricter immigration laws say allowing Dreamers to stay in the country would reward those who entered the country illegally and encourage others to do the same.

Texas U.S. Senator Ted Cruz, a Republican, has likened a legislative fix for Dreamers to amnesty and said it would hurt American workers.

"I do not believe we should be granting citizenship to anyone here illegally," Cruz said in a Feb. 15 speech on the Senate floor.

Many religious leaders disagree, saying Dreamers and other immigrants contribute to the country and are the epitome of the vulnerable the Bible calls on them to serve.

"We help refugees and immigrants not because they are Catholic but because we are," said Ashley Feasley, policy director for the U.S. Conference of Catholic Bishops' Migration and Refugee Services. "It is in the biblical tradition of welcoming the stranger."

STALEMATE: Immigration plans stuck in congressional limbo as deadlines loom

The ties between immigrants and churches go back to the earliest days of this country, where settlers often brought religious traditions from their homelands with them.

Many Protestant denominations formed in the Midwest, such as the Swedish Baptist Church (now known as the Baptist General Conference), had Dutch, German and Swedish roots, said M. Daniel Carroll Rodas, a professor of Old Testament at Wheaton College in Illinois and author of "Christians at the Border: Immigration, the Church and the Bible."

Catholic parishes have also long been immigrant enclaves, reflecting the changing waves of newcomers coming to the U.S. The Irish, Italian and German parishes of the 19th and early 20th centuries have given way to Mexican, Central American, African and Asian congregations.

Indeed, according to a Pew Research Center study, 39 percent of Christian immigrants identify as Catholic - and many churches have integrated cultural touches from their native countries into services.

The Archdiocese of Galveston-Houston has seven "ethnic ministries" for Hispanic, Vietnamese, African, Filipino, Korean, Chinese, Polish and Indian parishioners.

"Immigrants are reinvigorating a lot of churches," said Sam Dunning, director of the Office of Justice and Peace in the Galveston-Houston archdiocese. "As a 59-year-old white male, I find my faith continually enhanced and nurtured by the faith traditions they bring."

For Catholic leaders, immigration advocacy has always been an integral part of ministry, with some religious orders founded to assist newcomers. The Scalibrini Brothers, for example, helped Italians migrating to the U.S. from the end of the 19th century until after World War II.

Priests and nuns accompanied immigrants to this country and served them as they settled here, a mission that continues with more recent arrivals, said Sister Ann Scholz, associate director for social mission of the Leadership Conference of Women Religious.

"Our hospitals, schools, social service agencies serve communities in need and those tend to be immigrant communities," Scholz said. "It is still our call to work with the most vulnerable. The story of immigrants is our story."

The rise of evangelical and mainline Christian voices in the immigration debate has emerged as Latinos became a larger force in evangelical communities and as Christian churches began to grow more diverse, said Ali Noorani, executive director of the National Immigration Forum.

According to the Pew Research Center, around one in four evangelicals were nonwhite in 2014, compared to 19 percent in 2007. About 16 percent of evangelicals and about 14 percent of mainline Christians were first- or second-generation immigrants.

"That forced the evangelical leadership to look at the issue in a different way," said Noorani, who noted that the Southern Baptist Convention, as well as members of the President's Evangelical Advisory Board, have spoken out in support of Dreamers and other immigrants.

'Anti-American'

The presence of immigrants in congregation may also have helped shift attitudes of evangelicals on the issue of immigration. About 70 percent now say Dreamers should stay in the country, with about 49 percent in favor of a path to citizenship, according to a Politico/Morning Consult found.

Rodriguez, who says he has personally lobbied Congressional leaders and the president to find a solution for Dreamers, pointed to the anxiety felt by many in his congregation.

"Imagine, you are building the American Dream and you don't know if in 18 days ICE agents will be at your door," said Rodriguez. "This is so anti-American. It is morally reprehensible on steroids."

For immigrants, the embrace of the church is also serving as a buffer against anti-immigrant sentiment.

Ramirez, who entered the U.S. in August 2014 and spent 11 months in an immigration detention center with her son after an asylum request was rejected, said the sanctuary offered by St. Andrew's is light in a moment of darkness.

Ramirez, a Baptist, says her faith keeps her afloat. If God could create heaven and humankind, she believes, he will find a way to help people like her.