Apologies, I’ve not expressed myself clearly.
I don’t particularly like priest exactly because it sounds like you need to be an ordained minister that is part of an organised religion (and for me invokes a specific religion due to where I live, which I happily concede is personal bias, the same as any other opinion). It doesn’t fit the image of the paladin very well, for example, as you yourself note.
I would rather a term divorced from religion that still conveys faith. I liked the suggestion of Mystic, but there have been some other good ones too. That said, I’ll not lose sleep over it.