Valerie Powell stood at the back of St. Aloysius Gonzaga Church before Sunday morning’s service, preparing to say goodbye to a parish where she’d found her spiritual center for the past decade.

“It took me a long time to find this church,” said Powell, of the District. “I’m losing a home. . . . This is the first church where I walked through the door and people really welcomed me.”

Powell and more than 300 other parishioners and visitors gathered Sunday to celebrate the last Mass of St. Aloysius Gonzaga, the 153-year-old church at 900 North Capitol Street NW known to many as “St. Al’s.” It is merging with the nearby Holy Reedemer church because of a shortage of Jesuit priests.

The St. Aloysius building, which is owned by the Jesuits and is part of the Gonzaga College High School campus, will continue to be used by the school. Holy Redeemer will also use it for special services, weddings and funerals, parish officials said. The parish’s Father McKenna Center for homeless men will continue to operate.

But the eclectic congregation of about 250 households will cease to exist. Many who attended Sunday’s Mass hugged each other and dabbed at tears, saying the city has lost a parish heralded for cultural diversity, vibrant services and an unusually devoted service to the poor.

“We have White House staffers and people who are homeless worshiping in this church,” said Lynnly Tydings, of Takoma Park, who attended St. Aloysius for 21 years.

The parish, Tydings and others said, attracted many Catholics who felt uncomfortable elsewhere. About 90 percent of its parishioners came from other parts of the District and the suburbs, parish leaders said.

“This is a place where all of us who want to be Catholic can be, even if we don’t follow everything the church says we should be following,” Tydings said.

Parishioners said rumors that St. Aloysius might be closed circulated for years before the Jesuits announced the merger in June. Since 1965, the number of Catholic priests in the United States has dropped from about 58,600 to 39,000. The subsect of “religious priests,” which includes Jesuits and other religious orders, now numbers about 12,300, down from 22,700, according to the Center for Applied Research In the Apostolate at Georgetown University.

The Rev. Thomas Clifford, St. Aloysius’s pastor for the past six years, said he’s seen the number of Jesuits in the Mid-Atlantic region drop from about 750 priests and students to roughly 320 over his four decades in the priesthood. Nearly half are now older than 70, he said.

Clifford will soon begin a new assignment. He choked up as he spoke of St. Aloysius, where many white parishioners came for the swaying, hand-clapping gospel choir.

“People will grow into wherever they are [in new churches], but it’s an ending of this,” he said.

Susan Gibbs, a spokeswoman for the Jesuits, said St. Aloysius was closed because it was the smallest parish in the Mid-Atlantic. Because the church building is part of the high school campus and attached to the Jesuit teachers’ residences, the diocese could not put a non-Jesuit priest there, she said.

“It’s sad, and it’s hard,” Gibbs said. “They become priests to serve people. To realize you can no longer support all the ministries you used to support is extremely difficult.”

The Washington diocese has two remaining Jesuit churches: Holy Trinity Catholic Church in Georgetown and St. Ignatius Church in Charles County.

Several St. Aloysius parishioners said they felt abandoned by the Catholic Church. Teddi Ann Galligan, of the District, said she found it “heartbreaking and astonishing” that the parish where she’d been married and had two children baptized would close because of a shortage of priests.

If the Catholic Church allowed women and married people to be ordained, she said, “They’d never have to close a church for lack of a priest.”

Mary Ellen Krolman, chairman of the parish council, said the congregation asked that St. Aloysius stay open with visiting priests — including non-Jesuits — but the Jesuits rejected the idea. Krolman said she thinks about two-thirds of the parish will move to Holy Redeemer.

“We’re not leaving as solo operators, we’re leaving as a family,” Krolman said as the church began to empty out. “I think that will encourage people to stay with it. Will it be the same? Never. But I think we’ll survive and not only survive, but thrive.”