Belinda Bowden couldn't believe she was homeless. The 41-year-old had been ascending the corporate ladder, making $50,000 a year as a Kmart assistant store manager, when one by one the rungs snapped.

Asked to lie about the store's stability to potential employees, Bowden quit her job. Her savings account depleted by credit-card debt and medical bills, Bowden couldn't pay her rent. Two months later, she was standing on the street in DuPage County, Illinois, with her 11- and 13-year-old sons.

Bouncing between hotels and friends' homes, Bowden eventually found shelter at Bridge Communities, a transitional housing organization that began as a small-group project in a local church in 1988.

"God can scoop you out of the gutter immediately," Bowden said. Scooping people up is Bridge Communities' specialty. The $1.6 million nonprofit now owns 70 apartments—almost all leased to single mothers. The organization vets clients and provides counseling services. But they depend on area churches for most of the vital work, from mentoring residents to furnishing apartments.

Bridge Communities started 17 years ago with a heartrending story that inspired two men. Bridge cofounder Bob Wahlgren heard about a little girl who was living in a car in Glen Ellyn, a Chicago suburb, and attending school a couple blocks from his house. When the school found out that her family had been using a bogus address, her parents took the family and fled.

"I thought I was living in the suburbs where that doesn't happen," Wahlgren said. "I always felt we had a vibrant economy. [Suddenly] I felt like my town was more vulnerable—less secure—than I thought."

Wahlgren spoke with Mark Milligan, a fellow member of First Congregational Church ...