The Church of the Assumption gets its final shot at redemption Monday. That's when the Callowhill Neighborhood Association will make a last-ditch appeal to Philadelphia building officials to halt the planned demolition of the landmark Spring Garden Street church where the Catholic saint Katharine Drexel was baptized.

As hopeless causes go, the Assumption's chances look better than most. Not only does the ocher-colored church have a skilled and determined neighborhood group in its corner, it has the good fortune to be located in a reviving neighborhood, a brisk 10-minute walk from City Hall. It's true that its twin verdigris spires, beloved as a compass on the skyline, require serious repairs, but that hasn't made arts groups and developers any less eager to get their hands on the handsome building.

If only the hundreds of other crumbling historic churches, synagogues, and mosques in Philadelphia were so lucky.

Like most older cities, Philadelphia finds itself with an immense inventory of historic religious buildings, from lacy Gothic chapels to chocolaty Victorians to grand, Byzantine-inspired domes. They're a legacy of a time when people communed with their higher powers on a regular basis, and every neighborhood boasted its own distinct house of worship.

But for all the familiar reasons - demographic, social, spiritual - many of these sanctuaries will never again see their pews filled with worshipers. Some were shuttered long ago and left to the elements. At others, congregations manage to keep the doors open, but can barely afford basic maintenance. No one knows the precise number of troubled religious structures, but Robert Jaeger, who heads Partners for Sacred Places, estimates that about a third of the 1,000 historic religious buildings in Philadelphia - say 350 - are stressed near the breaking point.

So, even if the city's Licenses & Inspection Review Board - which hears appeals - does the right thing Monday and agrees to spare the Assumption, there are still 349 other historic buildings that need a rescue.

You don't have to be a believer to worry about their fate. Just imagine how dreary Philadelphia's neighborhoods would be without the tapered spires and crenulated towers to puncture the rowhouse sameness. They stand out as examples of real craft in an era when everything new seems to be made of plastic. Religious buildings, like libraries and schools, offer us a reflection of our better, nobler selves.

These mighty structures were constructed when the city itself was mighty, between the middle of the 19th century and the 1920s. But that means most of the cohort is now well into its second century of life.

To understand the problem, Jaeger's group, which promotes the preservation of religious structures, decided in 2002 to assess the condition of a dozen churches in North Philadelphia. All were grand venues built by white congregations and passed on to African American ones. Partners for Sacred Places found half suffered from serious structural problems, while all had inadequate wiring - a major cause of fire.

When Partners went back recently for a follow-up, this is what it found: One of the 12 - Christ Temple Baptist, by the great ecclesiastical architect Samuel Sloan - had been demolished. Another, a former Catholic church in Brewerytown, had lost its towers. The rest had suffered various degrees of dismemberment. None had undergone significant repairs. Jaeger presumes the results of the sampling can be extrapolated to the whole city.

The Assumption's decline followed the typical pattern. After being desanctified by the Catholic archdiocese, the 1848 church building designed by Patrick Charles Keely, along with its equally beautiful rectory and school, was sold in 2006 to a small nonprofit called Siloam. Unfortunately, the agency could barely tend to its needy clients, never mind manage a large real estate complex. When engineers ordered $1.5 million in urgent repairs, the owner instead petitioned the Historical Commission to demolish the church, the oldest building on Spring Garden Street. The request was approved in September by one vote, after the normally nonvoting chairman cast the tiebreaker.

Similar stories can be told about dozens of churches in what the independent website calls the "North Philadelphia Swath of Destruction."

Norris Square, one of the few English-style city squares outside Center City, seems destined to lose St. Boniface, a regal brownstone that defines the park's southern edge. In this case, the city and the neighborhood group are enabling its demise in the hope of building housing on the site. Meanwhile, in South Philadelphia, Metropolitan AME Zion, a modest brick church at 20th and Fitzwater Streets with a great history, was leveled last month, supposedly to make way for a developer's rowhouses.

With the battle for the Assumption, preservationists have drawn a line in the sand: No more mindless demolitions.

The Callowhill neighbors want to see the Assumption as an anchor for the neighborhood's revival. They believe it could be sold to a private owner such as the Clay Studio, which has considered it as a potential location for a gallery. Only two blocks away, on Broad Street, developer Eric Blumenfeld is turning the former Wilkie Buick into a high-end food emporium, while a group of New York investors has purchased the 10-story Independence Press at 11th and Brandywine Streets for apartments.

Dozens of other Philadelphia churches have been converted to housing, meeting halls, and child-care centers. More tricky is coming up with strategies to help small congregations maintain their grand homes for religious purposes.

Both Partners and the Preservation Alliance have been working with churches to teach them basic survival strategies. They urge them to share their space with other religious groups, arts organizations, or nonprofits. Besides earning a little rent, it helps to reinforce the building as a community center and makes it easier to solicit grants for repairs from foundations. Getting on the National Historic Register can also open doors to funding sources. These days, marketing skills are as important as preaching skills.

The battle for the soul of the city's religious buildings promises to be a long and difficult one. There will certainly be casualties. But the first salvo will be fired Monday, at 10 a.m., at 1515 Arch St.