The caucus, a formal congressional group Forbes founded in 2005 , helps the Chesapeake congressman fight what he calls the “constant, dripping erosion” of the nation’s heritage of prayer and faith.

Just last month , the caucus swung into action when an official deleted “God” from a certificate accompanying a flag flown over the U.S. Capitol .

The caucus is bipartisan, but most of its 25 members are evangelical Christians representing districts “with siz able populations” of evangelicals, she said. The group includes at least one Jew and one Catholic. ...