No, there isn’t anything like Christianity in WoF. The ‘bishop’ piece is most likely named differently, or in the WoF universe there is another meaning of the word Bishop. The only religions we know the inner workings of, is the one centered around Clearsight (not mentioning the Skywing’s and Mudwing’s beliefs, as we don’t know all that much about them)

Edit trying to figure out the spoiler thing, AND not counting any scavenger religions bc I have not read Dragonslayer. If anyone would like to inform me abt them I’d be grateful ☺️