In recent years, the specter of litigants turning to religious or customary sources of law as authoritative guides to regulate their behavior, alongside or in lieu of secular norms, has risen to the forefront of politics in many countries worldwide. In this essay, we draw upon citizenship theory and comparative constitutional jurisprudence to identify two different categories of judicial response to religious-based claims for recognition, accommodation, and exemption: 1) 'diversity as inclusion;' and 2) 'non-state law as competition.' As long as legal claims for accommodation are not seen by courts as challenging the lexical superiority of the constitutional religion itself ('diversity as inclusion'), they stand a fair chance of success. Contrast that with the unyielding reluctance of legislatures and judiciaries to accept as binding or even cognizable any potentially competing legal order that originates in sacred or customary sources of identity and authority. This pattern of clamping down and refusing to accept any alternative sources of regulation becomes particularly visible where the legal challenge at issue is interpreted as raising doubts regarding which set of norms and institutions, or what set of high priests, should have the final word in authoritatively resolving legal disputes within a given society ('non-state law as competition'). This is a challenge that no secular legal order, no matter how tolerant and otherwise open to providing exemptions and accommodations to religious believers, can accept with indifference. For what perceived to be at stake here is the very authority and source of legitimacy of the accepted civil religion. We demonstrate these claims by focusing on recent jurisprudence from Canada and South Africa, two polities that represent the most difficult cases for our argument; if there is any place we would expect to find recognition by secular countries of religious or customary sources of law and authority, it would be in these diverse societies that have made an explicit constitutional commitment to promote their citizens’ freedom to preserve and enhance their multitude of backgrounds and distinctive cultural, linguistic and religious heritages as part of their 'mosaic' (Canada) or 'rainbow nation' (South Africa) conceptions of citizenship. Although operating in different contexts, the South African Constitutional Court and the Supreme Court of Canada seem to have made every effort to subject traditional legal regimes to general principles of constitutional law. By so doing, they have erected a new wall of separation that places noncompliance with the values of the civil religion beyond the pale of accepted accommodation, offering to those who espouse them the potential to either bring these alternative legal domains under the general rule of constitutional law or encounter the wrath of state fiat.