The concept of 'civil religion' suggests that a pervasive, nonsectarian understanding of morality and transcendence sacralizes the nation-state, the polity, and the history and destiny of a society. The concept became popular in social science circles following Robert Bellah's (1967) article. Civil religion has generally been credited with functioning as a source of cohesion and coherence in political life. However, recent empirical and theoretical developments have undermined the notion that civil religion is inherently an expression of social solidarity. We first explore definitional distinctions in the literature on civil religion, focusing on the United States, where the concept became important for understanding 'American exceptionalism' with regard to religiosity. We then turn to three developments that complicate the use and application of the civil religion concept as initially formulated: increasing religious pluralism, increasing religio-political polarization, and cross-national comparisons.