While Wiccans may have originated the term "fluffy bunny," nominal adherents of more mainstream religions, particularly Christianity, are often fluffy bunnies as well. While they may have rejected anything resembling the theology of their chosen religion, or may not have bothered learning it in the first place, they believe with perfect faith in their self-identification with that religion, as well as in their homemade God who backs up everything they say.
For example, on another site, I have encountered many self-identified Christians who believe that the Bible is only partially God's Word; by some odd coincidence, the parts that they like are both Divinely inspired and Divinely preserved, whereas the rest of it isn't. They know this because "God" speaks to them and tells them which parts to follow and which to ignore. If you know such people, you know that it does no good to point out that "God" speaks to many other people, including other people on the same board who hear from "God," and tells them mutually exclusive things. They either don't understand or don't care that any "God" that so consistently contradicts both itself and its own holy book isn't God at all.