Dragon 328 has Peripheral Beliefs. Daily Prayer, Day of Rest, Dietary Restriction, and Sacred Clothing.
I'd say Bard or Cleric is your best bet for classes. Bard is charisma based, and a Lore bard fits pretty well. intelligence however should be higher, as should wisdom. Feat-wise Inspiring Leader, Linguist, Prodigy, Ritual Caster, and Skilled all fit well. Cleric cantrips are pretty decent for this concept: Guidance, Spare the Dying, Thaumaturgy, Word of Radiance. First level spells that fit the theme include: Bless, Ceremony, Command, Detect Good and Evil, Guiding Bolt, Protection from Evil, Sanctuary, Shield of Faith. Bard has some spells that fit too, like (in addition to overlapping cleric spells): Comprehend Languages, Friends, Identify, Illusory Script, Light, Message.
Whoops just realized you were asking in a 2e context. Sorry about that, I gave a mostly 5e focused answer. Maybe it can help a bit with some themes and ideas that can be adapted for 2e.