This landmark study in the sociology of religion sheds new light on the question of what has happened to religion and spirituality since the 1960s in modern societies. Exposing several analytical weaknesses of today's sociology of religion, presents a new theory of religious-secular competition and a new typology of ways of being religious/secular. The authors draw on a specific European society (Switzerland) as their test case, using both quantitative and qualitative methodologies to show how the theory can be applied. Identifying four ways of being religious/secular in a modern society: 'institutional', 'alternative', 'distanced' and 'secular' they show how and why these forms have emerged as a result of religious-secular competition and describe in what ways all four forms are adapted to the current, individualized society.