Correctly, the commission's stance is that, as regulator, it's not in a position to judge the truth claims of any religious organisation - only whether its activities are for the public benefit. Legally, it's not faith that falls under the remit of public benefit but the actions of the faithful.
Long before the advent of the controversial 2006 Charities Act, this had been established in case law. The presumption of the public benefit of the advancement of religion was variously interpreted. Basically, when not engaged in education or the alleviation of poverty, three questions had to be satisfied: is the body associated with a religion? Will it advance religion? And, in so doing, will it provide a public benefit?
The first two can be understood roughly as follows. Although the courts have excluded mavericks such as the Church of Scientology, modern charity law recognises a plurality of religions. As for advancement, most religious activity is deemed prima facie to be for the public benefit so long as it benefits enough of the public, which means that purely private benefits will not satisfy the test.
This public benefit business is tricky, but you really hit a nerve when you discount essential elements of religious experience. The classic here is the case of Gilmour v Coates: a benefit won't be recognised as public if it relies on metaphysical causation, such as prayers for the world by cloistered nuns. Does prayer work? Who knows? The activity would be accepted as religious in a general sense, but not charitable in a legal sense.
Likewise, there's scant evidence that, say, faith healing works - and it may even stop people seeking the medical help they need. And although proselytising is fine, so long as it doesn't involve bribery, brainwashing or violence, does any public benefit accrue from converting people from one religion to another? Religion: yes. Advancing it: yes. Public benefit: hmm. Perhaps for faith groups wishing to be charities, salvation lies in doing good works.
Nick Seddon is an author and journalist. Email him at firstname.lastname@example.org