REYNOSA, Mexico – Two long lines of migrants waited for blessings from visiting Catholic priests celebrating Mass at the Casa del Migrante shelter in this border city, just across the bank of the Rio Grande from Texas.

After services ended last week, several crammed around the three Jesuits again, asking about upcoming U.S. policy changes that would end pandemic-era asylum restrictions. That's expected to result in even more people trying to cross the U.S.-Mexico border, adding to the already unusually high apprehension numbers.

“All of you will be able to cross at some point,” the Rev. Brian Strassburger told the nearly 100 Mass goers in Spanish while a Haitian migrant translated in Creole. “Our hope is that with this change, it will mean less time. My advice is, be patient.”

It is getting harder to deliver that message of hope and patience not only for Strassburger, but also for the Catholic nuns running this shelter and leaders from numerous faith organizations who have long shouldered most of the care for tens of thousands of migrants on both sides of the border.

Migrants here – mostly from Haiti, but also Central and South America and more recently from Russia – are deeply mistrustful of swirling policy rumors. A judge has ordered the restriction known as Title 42, which only affect certain nationalities, to end Wednesday. But the asylum restriction, which was supposed to lift in May, is still being litigated.

Faith leaders working on the border are wary of what's to come. They expect tensions will keep rising if new restrictions are imposed. And if not, they will struggle to host ever larger numbers of arrivals at already overcapacity shelters and quickly resettle them in a volatile political environment.

“People are coming because it’s not long before the bridge will be opened. But I don’t think that the United States is going to say, ‘OK, all!’” said the Rev. Hector Silva. The evangelical pastor has 4,200 migrants packed in his two Reynosa shelters, and more thronging their gates.

Pregnant women, a staggering number in shelters, have the best chance of legally entering the U.S. to apply for asylum. It takes up to three weeks, under humanitarian parole. Families wait up to eight weeks and it can take single adults three months, Strassburger explained at Casa del Migrante, where he travels from his Texas parish to celebrate Mass twice a week.

Last week, the shelter housed nearly 300 people, mostly women and children, in tightly packed bunk beds with sleeping pads between them. Men wait in the streets, exposed to cartel violence, said Sister Maria Tello, who runs Casa del Migrante.

“Our challenge is to be able to serve all those who keep coming, that they may find a place worthy of them. … Twenty leave and 30 enter. And there are many outside we can’t assist,” said Tello, a Sisters of Mercy nun.

Edimar Valera, 23, fled Venezuela with family, including her two-year-old daughter. They crossed the notoriously dangerous Darien Gap, where Valera nearly drowned and went without food. After arriving in Reynosa and escaping a kidnapping, she found refuge at Casa del Migrante, where she's been since November despite having a sponsor 10 miles away in McAllen, Texas.

“We need to wait, and it could be good for some and bad for others. One doesn’t know what to do,” she said, finding some comfort in Mass and daily prayers, where she begs God for help and patience.

So does Eslande, 31, who left Haiti for Chile. She is on her second attempt to cross into the U.S. after not finding there the right help for her young son's learning disability. At Casa del Migrante just a day, she read the Gospel aloud in Creole during Mass, a reminder of happier times when her father distributed Communion.

“I have faith that I will be going in,” she said in the Spanish she’s learned en route. Like many migrants, she only gave a first name fearing for her safety.

Tensions are rising faster than hope as it's unclear who will be able to cross first.

“Any change could grow the bottleneck,” said the Rev. Louie Hotop, dropping off hygiene donations at one of Silva’s shelters – a guarded, walled camp with rows of tents pitched tightly together.

Even if Title 42 is lifted and thousands more are allowed to enter the U.S., asylum-seekers would still face enormous backlogs and slim approval chances. Asylum is granted to those who cannot return to their countries for fear of persecution on specific grounds – starvation, poverty and violence don’t usually count.

It's a long, uncertain road ahead even for the roughly 150 migrants at a bare-bones welcome center in McAllen, Texas, where the Jesuit priests stop after their Reynosa visits. Families legally admitted to the United States, or apprehended and released, rested in the large Catholic Charities-run hall before traveling to join sponsors.

Lugging their Mass kit and heavy speakers, the priests offered migrants spiritual and practical help – like writing “I’m pregnant. Can you ask for a wheelchair to bring me to my gate?” on a paper for a Honduran woman eight months pregnant with her first child and terrified about airport travel.

“It’s a way of listening, of supporting, it’s not so much resolving the immediate problem,” the Rev. Flavio Bravo said. “They bring stories of trauma, of life, that we must give value to.”

Sister Norma Pimentel, a prominent migrant rights advocate who first helped border crossers four decades ago and now runs Catholic Charities of the Rio Grande Valley, said religious people should push for centrist reform to help migrants – not make them political pawns.

“Policies don’t respond to the realities we’re facing,” said Pimentel, who opened the welcome center in 2014 for the first big asylum surge of this century. “It’s impossible to help everyone … but who are we to limit the grace of God?”

Now, the busiest crossing is some 800 miles away in El Paso, Texas, and neighboring Ciudad Juárez, Mexico. Ronny, 26, turned himself into U.S. authorities there and was flown to McAllen because “around Juarez it was collapsing,” he said last week at Pimentel’s shelter.

He and his family left Venezuela on foot in September because he opposed his country's regime and his wages were too low to afford food. He has a U.S. immigration appointment next month in New York where his sponsor lives, but no money to get there.

On his first free night in the U.S., he turned to God, following Mass from a distance so he wouldn't leave the thin mat where his children slept.

“We ask God for everything. Always,” he said.

Associated Press religion coverage receives support through the AP’s collaboration with The Conversation U.S., with funding from Lilly Endowment Inc. The AP is solely responsible for this content.