Using the Brazilian case as a reference, this chapter demonstrates that since the country’s first republican constitution, “religious diversity” was legally constructed as a form of allocating, in the field of religion, popular practices perceived as dangerous and or superstitious. My hypothesis is that this religious diversity does not at first signify pluralism, given that it was organized under the aegis of Catholicism, within the ideology of syncretism. Using the constitutional congress of 1988 as an important point of inflection in the form of treating differences, I argue that since this time, pluralism became instituted as the main legal and political organizer of differences and particularly of religious diversity. Associated to the decline of the hegemony of the Catholic Church, this principle, by defining religions as relative to each other, promotes competition among religious organizations for social influence and primacy in their relationship with the state.