How to judge religions other than one's own when facing a plurality of religions? The author makes a philosophical inquiry in two interconnected fields, linguistic undecidability and the necessity of making judgements. The central claim is that no stable centre for meaning can be established for linguistic entities. Even in cases where a stable centre of meaning would seem to be required, the author argues that linguistic entities in fact have to be mobile, in order to allow for newness in interpretation and understanding. Without such mobility, language would cease to function as language. A related concern is: Does truth entail justice? The author argues that it is not enough to possess true knowledge when making normative judgements. Ultimately, it is argued, judgements are made by persons, not impersonal principles. In closing, the focus of the inquiry is brought back to the concrete question of religious diversity. While this study mainly offers a fresh philosophical approach to issues of religious diversity, its line of argument relates to a number of topics well beyond its primary scope.