This essay examines studies of trends in religion and religiosity, concentrating on the case of the United States but periodically comparing that country to other societies as well.

The summary of research opens with an overview of the putative wisdom received from the once-dominant belief in the process of secularization. It proceeds to a consideration of American habits of religious affiliation and switching, followed by a discussion of rates of participation in religious activities (most notably, the reported reductions across denominations in attendance at church services over the past half-century). Featured next are recognition of the rising proportions of people who claim no religious preference at all and of those who adhere to a world faith other than Judaism or Christianity.

Finally, the narrative ventures several informed predictions concerning the contours of religion's future and concludes by identifying some of the theoretical and methodological challenges that any disciplinary or interdisciplinary understanding of religion will confront in a changed and changing world.