I've heard "racist" being used in a few cases to describe bigotry towards people of a certain religion. It's a bit annoying because it implies that all people of a religion are the same race, which is hardly the correct case. However I'm also bewildered that there doesn't seem to be an appropriate one-word substitute coined to describe prejudice/discrimination/sense of superiority in terms of religion. What (if any) word exists for it?
- Antitheism - opposition to belief in a deity (or deities)
- Antireligion - opposition to organized religion
- Anti-Judaism/Anti-Judaic - opposition to Judaism
- Anti-Christian [sentiment (n.)] - opposition to Christianity
- Anti-Islamic/Anti-Islamist - opposition to Islam
Other words exist such as Islamophobia, but that could perhaps be considered different because it's a fear of something, which might be considered different than simply hating it.
These terms are also specifying a specific religion or all religion. Other terms that denote hatred for all religions other than one's own, such as "religious intolerance", "religious bigot", etc. have already been given.
Triumphalism may be what you are looking for. It denotes the sense of religious superiority that you are looking for in your word, however it does not necessarily imply an attitude of bigotry towards people of other religions/denominations.
Answer moved from another question ("Race is to Racist as Religion is to What?") closed as a duplicate, hence the mismatch racist > racism and the apparent duplication of the 'sectarian' answer from an earlier answer
The word 'sectarian' is, of religion, closest to parallel with 'racist':
3. A bigoted adherent of a sect; one whose views or sympathies are sectarian.
["sectarian, adj. and n.". OED Online. September 2015. Oxford University Press. http://www.oed.com/view/Entry/174583?redirectedFrom=sectarian (accessed December 08, 2015).]
'Sectarianist' is also in use. Examples include
(From Dialogue and Universalism, Volume 6, Issues 7-12, Warsaw University, Centre of Universalism, 1996.) And
Nobody who can see and write so brilliantly and fearlessly about the evils of religion as he had done would take back what he said just like that. How can a highly spiritual person like him suddenly reduce himself to a mere sectarianist?
(From Transcending Rizal, Margarita Ventenilla Hamada, Giraffe Books, 2005.)
'Sectarianist', however, has not established itself in dictionaries, although the intended meaning is clear.
Note - I posted this answered against a later question which I didn't realise was a duplicate. I don't know if it's considered "good form" to duplicate an answer, but I've copied it here because it seems extremely relevant, and at time of writing I don't see the word "Dawkins" anywhere on this page.
Religious intolerance/discrimination are well-established, but so far as I'm aware they are mainly used in contexts where people of one religion don't like people who believe in a different religion.
I'm not entirely sure whether the man himself would endorse the categorisation, but...
...is certainly gaining considerable currency.
It's mainly used by people who are religious, and hence consider the word to be inherently derogatory. In which context, it's worth noting that the -ism suffix is often used in terms denoting a form of discrimination, or wild or visionary theory. By extension, the actual word "ism" is often used in a negative sense.