Correction: Earlier versions of this article, including in Monday’s editions of The Post, incorrectly reported that Catholic officials plan to release next month a specific number of Episcopal churches that are expected to join Catholicism. The announcement is to come this week. The article also incorrectly reported the first name of the Rev. Scott Hurd. This version has been corrected.

An Episcopal church for more than a century, St. Luke’s in Bladensburg added a new prayer to its routine Sunday: “for Benedict, our pope.”

It was the first Sunday Mass since St. Luke’s made international news by announcing it would become the first Episcopal parish in the United States to convert to Catholicism under a new Vatican structure meant to attract orthodox Anglicans. The Episcopal Church is the U.S. wing of the Anglican Communion.

It was also the first Sunday that parishioners such as Ada Okafor, an Anglican since her childhood in Nigeria, used Vatican-approved prayer books.

“It felt fine,” Okafor, a credit union supervisor from Lanham, said of the prayer for “her” pope. “I made a conscious decision, and I’m looking forward to being brought along.”

Over sheet cake and lemonade in the church basement after Sunday services, congregants heard about the more than 300 people from around the world who had e-mailed St. Luke’s since the news broke. The date set for the parish’s formal conversion to Catholicism is Oct. 9.

In a nation of faith shoppers and switchers, St. Luke’s congregants see their decision as profound, a choice between fuzzy theology and clear authority. But much of their practice won’t change when they become Catholic. That’s because St. Luke’s is Anglo-Catholic, a movement that tends to attract traditionalists who love the elaborate ritual of Anglican liturgy but also like the Catholic concept of one Christian leader.

The new prayer book deliberately read almost exactly like the one St. Luke’s used before — the Anglican Service Book, which is favored by traditional Episcopalians.

The decision by St. Luke’s attracted attention partially because the entire church is converting — including its married pastor. But it also stands out because several conservative Episcopal congregations, angered by the election of an openly gay bishop, voted in recent years to leave for other wings of Anglicanism, mostly in Africa.

Experts say the likelihood of more Episcopal churches joining Catholicism is small, but Catholic officials plan to release a more specific number this week. Cardinal Donald W. Wuerl, Washington’s archbishop, is the Vatican’s U.S. leader on the effort.

Whatever changes are in store for St. Luke’s, they will begin soon: Congregants start conversion classes this month.

Members are onboard with key ideas such as papal supremacy, and they overwhelmingly voiced their support a week ago when rector Mark Lewis announced that a deal had been struck between Episcopal and Catholic leaders to separate peacefully and without fighting about property.

But congregants noted Sunday that many at St. Luke’s aren’t accustomed to practices such as Confession — required in Catholicism — and praying the rosary. Some might have reservations about Catholicism’s reverence for Mary. What will happen this summer, they said, isn’t totally clear.

“I think the journey has actually just begun,” said Randy King, a defense contractor from Crownsville. “We’ve always been Anglo-Catholics, but did people really know what that was? Now they’re going to find out. And there may some who say: ‘I don’t want to be outside the Anglican Communion. That’s where my father and grandfather were.’ ”

The process was underway during the basement lunch, with the Rev. Scott Hurd, Wuerl’s assistant for converting Anglican parishes, telling congregants about the classes that were about to begin and explaining a few basic Catholic terms.

“Thank you for your courage and faith,” Hurd said. “It’s a wonderful thing to behold.”