Elrond: Roman Catholic

Aragorn: based on his upbringing, also Roman Catholic

Thranduil: literally started a cult of himself

Legolas: pretends to follow his dad’s cult, secretly a Methodist

Boromir: Lutheran like the good son of Gondor he is

Galadriel: Eastern Orthodox for the aesthetic

Bilbo: Anglican, a.k.a. he tried and failed to replicate Rivendell’s Roman Catholicism upon returning to the Shire post-BoFA

Frodo: Anglican with Anabaptist tendencies (was an acolyte growing up)

Sam: Quaker but will break his pacifist streak to defend Frodo

Merry: progressive exvangelical with a passion for social justice

Pippin: Unitarian Universalist

Gandalf: atheist despite literally being a divine messenger

Theoden: TULIP Calvinist