On Sunday mornings at Old St. Joseph's Roman Catholic Church, parishioners say, you can see something you wouldn't have seen a few years ago:

Baby strollers. Parked in the courtyard.

Their presence is a small but telling sign of how Philadelphia's oldest Catholic church is accomplishing a feat that vexes so many others - attracting young members.

"It's very important to us," said Louise Cruz-Vizcaino, who has attended Old St. Joe's for 25 years. "You need the longtime members to give support and encouragement, to be the mentors, but you need the young ones to give new blood. "

In the last year, the church has registered 159 parishioners - more than half between the ages of 21 and 39, bringing its congregation to 1,172.

Attendance at the Children's Liturgy of the Word on Sunday mornings has grown from five to 25. The class once fit easily into a rectory parlor, but had to be moved to a larger hall.

How did this happen in an era of graying congregations?

Not by accident.

In December, after considerable internal discussion, the church added a fourth Sunday service - at 6:30 p.m. The logic was simple: Young people are out on Saturday nights and sleep late on Sunday mornings.

Average attendance at the Mass, and spaghetti dinner afterward, has grown to 75 people, many of them young men and women.

"I'm confident if we didn't offer that Mass, they wouldn't be there," said the Rev. Mark Horak, who became pastor at Old St. Joe's in the summer of 2003. "You've got to meet them on their own terms. "

Feeling welcome

To get to Old St. Joe's, you wander down Fourth Street and turn hard toward the river, stepping across the cobblestones of Willings Alley, eventually reaching a narrow archway that marks a brick courtyard.

Philadelphia essayist Agnes Repplier famously described Old St. Joe's, founded by Jesuits in 1733, as being "as carefully hidden away as a martyr's tomb in the catacombs. "

"It's a place where I have always felt welcome, even if I didn't know anyone," says Patrick Britton, 24, who attends with his wife, Katie Higgins, also 24.

He recalled his first visit, how guests were asked to stand at the end of the Mass. He felt awkwardly

singled out, but "then everyone started clapping. "

"It just felt so genuine," Britton says. "They do their best to care about you as a person, and live out their faith and express their Catholicity in their actions. That has a big appeal to young folks: They may not know all the words or rituals, or when to stand up or sit down, but they don't have to. "

No doubt the church's efforts have been helped by the city's changing demographics: thousands of people in their 20s and 30s arriving amid a Center City renaissance that has spawned scores of restaurants, clubs and condominiums.

Old St. Joe's is a parish "without boundaries," which means worshippers can come from anywhere, and they do, from as far away as Lansdale. It also means they can leave when they want.