Amendments to secularization theory have brought the issue of public religions to the fore in recent years. In particular, the work of Casanova and Beyer has maintained the importance of functional differentiation whilst pointing to the flow of religious discourses across social boundaries. These issues, however, have received little ethnographic attention, such that many of the problems associated with theories of differentiation and globalization have not been engaged in a sustained manner. Research within black majority London Methodist congregations is drawn upon to suggest ways in which these theories can be reconsidered. Three related issues are focused upon: the continued importance of the nation-state (including national stratifications); the importance of a practical approach to religion, such that discourses are understood as ‘practical discourses’; and the importance of not privileging religion by reifying it in functional terms. These considerations have ramifications not only for secularization theory, but the general field of the sociological study of religion.