This article examines how judges in different countries treat "religious questions", as opposed to "legal questions", through the lens of one particular type of dispute: the expression of religious identity by wearing religious dress in public schools, contrary to state educational policy with secular democracies. Like the 'political questions' doctrine, issues of institutional competence and propriety arise in relation to the extent to which courts should engage with religious laws and reference these in developing public law norms. Much turns upon understandings of what the principle of secularity requires in a particular jurisdiction and the particular type of religious question implicated. It argues that while it is inappropriate for judges to address normative religious question which engages some form of theological inquiry, judges may have competence to address positive religious questions relating to the content of religious doctrine or the centrality of a practice to a religious community through reliance on expert evidence. Nevertheless, prudential considerations may still urge judicial self-restraint when address religious questions.