ST. LOUIS — The sun sparkled through the stained glass at St. Wenceslaus Catholic Church with a newness that belied the nearly century-old age of the windows. Red, blue, yellow and violet hues lit up the historic church, which was founded in 1895 by Bohemian immigrants.

The stained glass was designed by famed artist Emil Frei Sr., in the 1920s, when the current church building was constructed. It was restored years later by Frei’s company, which had been handed down to children and grandchildren.

Frei was a German immigrant who settled in St. Louis and designed some of the most famous stained glass windows and mosaics in the city long known as the Rome of the West.

At St. Wenceslaus, the sun highlighted the brilliant colors of those windows on Saturday, just a few hours before Archbishop Mitchell T. Rozanski announced the planned closure of 35 parishes, five mergers of 15 parishes, and reassignment of 155 priests in the St. Louis region.

I was there for a renewal of vows of friends celebrating their 25th anniversary. The Rev. Philip Sosa celebrated the wedding Mass in Spanish, which is not uncommon at the church in the Benton Park West neighborhood. St. Wenceslaus is one of two southside St. Louis Catholic churches — St. Cecilia is the other one — to host a Spanish language Mass each week.

Having grown up Catholic, I know there is a rhythm and structure to a Mass that is comforting, even when I don’t understand the words being spoken. Sitting in the church that now serves a new immigrant population took me back to the words of Archbishop Rozanski when the “All Things New” process began.

“We are still relying on a model of church that is based on an 18th century European model,” Rozanski told me more than a year ago.

In that model, immigrants to a particular area of a city and their families were continually replenishing the congregation. “That model is over,” the archbishop said.

The German and Slavic immigrants who once filled multiple churches in this part of the city have given way to new generations that moved to the suburbs — hence the need to consolidate and close parishes, and upend the spiritual lives of many of the region’s Catholics. But it’s not like Saturday’s moves were the first time it happened.

The history of St. Wenceslaus, for instance, is one of constant change. The elementary school opened and closed, and then reopened and consolidated several schools under a new name. Since 2005, the last time there was significant consolidation of parishes, the church has been designated a “personal parish,” one that can draw from outside its geographic boundaries.

St. Wenceslaus, which is staffed by priests from the Missionaries of the Holy Family, escaped any changes in Saturday’s announcement.

But another historic church not far away, Sts. Peter and Paul in Soulard — established in 1849 — couldn’t survive the latest consolidation. The church’s chapel will remain, but not as a stand-alone parish with weekly Masses.

The basement of that building tells a story about the church’s mission, and the story shouldn’t get lost in the talk about boundaries and buildings.

The oldest overnight shelter for homeless people in St. Louis was founded at Sts. Peter and Paul more than 40 years ago and has been operating ever since. Most nights, the shelter is full to its capacity of 60 men. They sleep on bunk beds tucked so close together that the shelter has been looking for a new home to fill the growing need.

Finding such a home has been a struggle. At a community meeting in March, the nonprofit that runs the Soulard shelter, Peter & Paul Community Services, met with fierce neighborhood opposition to a plan to locate the new shelter in the old Sts. Mary and Joseph Church.

That church was founded in 1821, becoming the third Catholic church in the area, after the Old Cathedral and St. Ferdinand in Florissant. It didn’t survive a round of closures in 2005. But the building still stands, and it is large enough to hold a robust homeless shelter.

But there is no room at the inn, some neighbors said earlier this year. They vowed to fight a rezoning that would allow the shelter.

“It’s a tricky thing,” said Deb Cottin, Peter & Paul’s chief development officer, after neighborhood opposition doomed the planned move. “Most people want to help, but they don’t want to see the people getting the help.”

Unable to put an old church building back into community service, Cottin says her organization is still looking for a suitable property, with the help of “kind-hearted and understanding” folks in south St. Louis.

The quest reminds me of one of the goals Rozanski set for “All Things New.” Church leaders, he told me, need to get away from being “caretakers of buildings” and focus on being “ministers to people.”

Twice in the first 25 years of this century, the Archdiocese of St. Louis has closed a significant number of parishes in parts of the region where the need is highest.

This year, many of the parish closures and mergers are in north St. Louis and north St. Louis County. Only one is west of Interstate 270 in St. Louis County.

The dwindling congregation numbers might justify such a move. But it also raises a question that a new generation of Catholic faithful will have to answer.

As boundaries are redrawn, priests move and parishes close, who will serve the new immigrant populations and the folks seeking shelter in the shrinking Rome of the West?