Safia Yasmeen Without a context, there is no difference. In some context there could perhaps be a difference in emphasis, inasmuch as you might be focusing either on critical thinking that is about religion (religious critical thinking) or else focusing on religious thinking that involves thinking critically (critical religious thinking). But that's way too subtle a distinction to force upon a very similar form of words and very apt to be misleading or be difficult for your interlocuters to keep in mind. If you want to draw such a (or similar) distinction, I suggest you choose dissimilar wordings. On the other hand, if you are using the term "critical" ambiguously, then "critical religious thinking" might be construed as religious thinking that is, e.g., needed or important for averting a crisis, rather than merely well reasoned or logical. The important thing is to be clear and explicit about how you are using your terms and to not put an unnecessary burden on your interlocuters.