Faiza N. Ali paced across the plaza outside City Hall in Lower Manhattan, consulting a to-do list and juggling the messages on two BlackBerries. How was the turnout? Were the speakers prepped? One minister had already alerted Ms. Ali that he was running late. Another of her colleagues had gone to Borough Hall in Brooklyn by mistake.

On this blustery morning two weeks ago, Ms. Ali was undergoing one of the first tests of her new job as a community organizer, helping to run a rally in support of proposed legislation encouraging more local investment by banks. And by the time the hundred participants had assembled on the City Hall steps, Ms. Ali, a petite figure in a hijab, was standing beside a Catholic priest, holding the edge of a banner from Brooklyn Congregations United.

A Muslim trained by a Jewish agency to work with a coalition largely composed of Christian churches, Ms. Ali is not just the poster child for monotheism. She forms part of a vanguard of faith-based community organizers who have been selected in part for their religious devotion and then trained to cross denominational lines in pursuit of common cause.

“There’s a healthy tension,” as Ms. Ali, 27, put it, “when I want to talk about an issue campaign and the first line of questioning I get is, ‘What’s that thing you’re wearing and where are you from?’ I kind of anticipated those questions. It was a reminder of how few people have met Muslims. I can answer their questions and address the stereotypes head on and then do the work together. It’s created a different sense of community for me.”