Nearly 5,000 parishioners gathered Sunday at the Cathedral of Our Lady of the Angels in downtown Los Angeles for a Mass "in recognition of immigrants."
Among the attendees was Nick Sarmmartano, who said he came to the U.S. from Italy "to give my children an opportunity."
"My parents came here first, so I'm a little emotional, because I've seen a lot of people that have suffered a lot to come to this country," he said.
The standing-room only service, hosted by the Roman Catholic Archdiocese of Los Angeles, was marked by prayers for the thousands of undocumented children who have crossed the U.S.-Mexico border alone in recent months.
Church leaders told parishioners that many of the young immigrants were from Central America, sent by desperate parents to escape poverty and violence in their home countries.
"More of our fellow citizens seem to be losing faith in the spirit of America," said Los Angeles Archbishop Jose Gomez, an immigrant from Mexico, who led the Mass.
The border-crossing stories that were shared on Sunday evoked particular memories for two sisters in the congregation.
"I'm an immigrant. I came to the United States over 20 years ago" from Mexico, said Nora Placencia. She said people should be mindful "of how things are different for other people who don't have the privilege of being born in this country."
Her sister, Hilda Placencia, said immigration is "not just an out-of-the-moment thing."
"It's a process that a lot of us get denied," she said. "My dad was born here, and I wasn't allowed to become a citizen that way."
Not everyone was supportive of the sermon's message.
"The problems of the world can't be solved by just walking across the border ," said Michael Withrow, a church member who attended the annual event. "My Catholic leaders in many countries around the world aren't doing the job that they should be.
"It is not un-Christian for what we're trying to do to protect our citizens here," he added.
During Sunday's service, congregants were invited to organize training committees to support immigrants who want to apply for driver's licenses and deferred action for childhood arrivals.