You can call them “unaffiliated,” as in a recent Pew poll, or “nones,” or even just “not very religious.” A brand new poll by PRRI/Brookings divides this group further (and somewhat counterintuitively) into “unattached,” “atheists/agnostics,” and “seculars.”
Matthew S. Hedstrom
Matthew S. Hedstrom is Assistant Professor of Religious Studies and American Studies at the University of Virginia, and is the author of The Rise of Liberal Religion: Book Culture and American Spirituality in the Twentieth Century, to be published in November by Oxford University Press.