Definition of "delusion" in DSM-5

[Gawdzilla Sama]

I borrowed a copy of the DSM-5 from my university library today. In the glossary of technical terms, "delusion" is defined as

A false belief based on incorrect inference about external reality that is firmly held despite what almost everyone else believes and despite what constitutes incontrovertible and obvious proof or evidence to the contrary.

So far, so good. It then adds:

The belief is not ordinarily accepted by other members of the person's culture or subculture (i.e., it is not an article of religious faith).

Why do religious beliefs get a free pass? So if you're convinced Elvis Presley is still alive, you're delusional but if you think Jesus of Nazareth is still alive and can hear/answer your prayers, you're just a Christian. Why the double standard?

As I understand it religions got exempted in the first DSM for the delusion thing.