Late last month, two days before Christmas, the Rev. Dr. Katrina D. Foster, pastor of St. John’s Lutheran Church in the Brooklyn neighborhood of Greenpoint, was showing off her church’s recent renovations. The neo-Gothic church was built in 1891, and the original blue, vaulted ceiling; wooden pews; stained-glass windows; and a Jardine & Son pipe organ all looked relatively new.

“On Dec. 7 we had a huge rededication service,” said Pastor Foster, 56, who walked around the church with quick, sprightly steps and could not stop beaming. “It was the same day as Notre-Dame had theirs.”

Since 1994, when Pastor Foster was ordained, she has become known for her work turning around churches whose physical buildings and congregations are on the verge of collapse. She does it by community organizing and by building financial support for the church among churchgoers and the wider neighborhood.

“She’s often been entrusted with congregations that are struggling financially,” said the Rev. John Flack, pastor of Our Savior’s Atonement Lutheran Church in Manhattan. “She’s been able to do some pretty amazing stuff not just to keep them alive and keep them going, but even to thrive.”

She has mostly helped churches that she has led as a pastor. But other congregations have also recruited her as a consultant. “I have been invited to meet with congregations to talk about financial stewardship, evangelism, discipleship and building housing,” she said.

In November, Pastor Foster met with the leadership team of Our Savior’s, where, Pastor Flack said, she stressed the importance of showing the congregants that even small contributions could make an impact.