Yes, unless they can prove that they do something useful for society, like any other proper charity.
The British government ran into a huge problem with this one when it tried in 2006 to define what should be charitable. This hadn't been revised since 1601 so it was high time to look at it. The result was the prospect of private schools losing charitable status unless they do something more for the community than providing expensive education, so they all scuttled around trying to think of something such as letting people use their facilities cheaply or free.
And this also meant trying to define a religion, which they found they couldn't. There was a fun debate in the House of Lords on this. The previous definition defined a religion as an organisation that has public worship of one god, which excluded all the religions that have more than one god or no god at all, so that had to go. It did at least exclude that money-making scam called scientology. Eventually they found they couldn't define religion and left it up to the Charity Commission to say yes or no in individual cases, which ended up leaving everything as it was but meant the Commission now had no basis not to give tax relief to scientology. The best part of the debate was the realisation that there was no way to exclude Satanism from the definition.
The new law was on the right lines, though - allow tax relief if an organisation provides "public benefit". And just worshipping a god who doesn't provably exist does not, in itself, benefit the public.