The Brooklyn Tabernacle, a 3,500-seat evangelical prayer palace in downtown Brooklyn, was built in 1918 as one of the largest and grandest vaudeville houses in North America. It is still a hot ticket. Its youngish, racially diverse congregation packs the pews each week to praise God and bask in the sounds of a Grammy-winning 250-voice gospel choir. But the tabernacle is more than just a popular church. It is also a destination for evangelicals from all around the United States and beyond, laymen and ministers alike, who come as acolytes to study prayer.