Many are ignorant and believe childish things, many are similarly ignorant and live in the same childish framework only to condemn it. Then there are the adults, and they have an idea of what they are talking about.

It is not too different (attempting extra clarity) from people who would say "Oh but many think that AI is intelligent/not intelligent, <sneer>", but have little proper idea of matmul, of cognitive processes etc. (Imperfect simile, but may give an idea.)

The alternative is to believe that the mind, conditioned and optimized by millions of years of evolution for the survival of the organism under constant threat of hostile natural forces, can capably perceive reality as it is.

The reason is the appalling amount of existential dread that follows from accepting that notion.

> really mental institution level insanity except in the context of religion.

The DSM even has to include an explicit exception to prevent the clinical definition of “delusion” from applying to religious belief. Without that ad hoc exception, religious belief would be classified as clinically delusional.