A number of studies have found that religious “nones” -- people who either don’t believe in God or do not affiliate with a religion -- are increasing rapidly in the United States. A 2012 Pew study, for example, found this faction to be the fastest-growing "religious" group in America and determined that one in five Americans now identify with no religion.
MORE: http://religion.blogs.cnn.com/2013/01/25/none-leaders-to-chart-path-for-more-political-cultural-power-for-religiously-unaffiliated/