Organized religions such as the Abrahamic Religions had liturgical languages, such as western christianity using latin, islam using arabic, etc. Add liturgical languages as a religious doctrine, with the language having different effects depending on circumstances. Theocratic Clergy and Spiritual HoFs would always know the Liturgical Language in addition to their native language, I.E: the pope would always know latin. Lay Clergy and Temporal HoFs on the other hand must learn the liturgical language themselves if it is not their native language and will get a piety malus until they know the language. There would also be an option not to have a liturgical language at all for religions such as various forms of paganism or Manichaeanism. It would also allow more regional variation, such as Bulgarian Orthodoxy with Slavonic. Finally, having a language as your liturgical language could be a substitution for having it as your native language regarding Royal Courts, so that your islamic caliphate can speak Arabic even if it isn't your native language and you aren't in diplomatic range of a native arabic speaker.
#Liturgical Languages
merry harness
Here are also some ideas for what different religions and faiths could use as their liturgical languages:
Islam: Arabic
Judaism: Israelite
Zoroastrianism: Iranian
Taoism: Chinese
Western Christianity: Latin
Orthodoxy & Iconoclasm: Greek
Coptic: Coptic (would need to be added), Arabic (Language of Egyptian Culture), or Greek (Coptic was influenced by Greek language)
Nestorianism & Mandeaism: Aramaic
Apostolic: Armenian
Haymanot Judaism: Ethiopic
Nangchos: Tibetan
Manicheanism: None, it was a big deal that Manichean texts were translated to the contemporary language rather than having a liturgical language.
cunning ore
I would rather have not speaking the liturgical language be a piety malus for Lay Clergy and temporal HoF. To speak it is expected : it's not particularly pious to know it, it's just normal. Not knowing it is impious though.
Also it could certainly be a faith doctrine. You could change it when making a new faith by either replacing it with one of your known language, keep it as is, or remove it altogether. Maybe have some conversion bonus if you remove it or something
merry harness
Yeah, good point about losing piety for not knowing the liturgical language
dapper yew
One idea would be that unreformed faiths would not have an official liturgical language, it would instead be something you would get to decide upon reforming the religion(limited by the languages your character speaks and with your character's native language being set as the default).
safe stirrup
hmmm, idk about Greek as Orthodox's liturgical language as while that might be true for Byzantium, Orthodox Slavs should have Church Slavonic as the liturgical language
chrome flare
Orthodox Slavs Liturgical language could be solved by an event splitting orthodoxy when a Slavic ruler converts to it for the first time. though that might be only a 867 thing as i rarely start in 1066 and so is not overly familiar with the start date
merry harness
old post, but yeah. I mentioned that the bulgarians can make an offshoot of orthodoxy using slavonic as the liturgical language, and from there it can spread to the other slavs
safe stirrup
idk if an offshoot is worth making a separate faith in this case