Of course it's possible. That's not the point. The point is that "pernicious delusion" is pejorative in much the same way that "idiot" is (which is why I extrapolated it that way). Both imply some sort of mental deficiency or disorder. If someone believes in God, on this view, it can only be because their brains are broken.

To be sure, some people do have broken brains, and some people believe in God as a result. The hypothesis that I'm advancing here is that some people may believe in God not because their brains are broken, but because they have had (real) subjective experiences that non-believers generally have not had.