By RoP:I p.88f False Powers:
... the troupe may not allow it to apply to Virtues derived from the Divine.
But The Church p.85ff The Corrupt proposes three Religious Orders, that in a specific saga might have fallen to Infernal corruption.
Falsely believing to have ArM5 True Faith were an extreme kind of bigotry going beyond The Corrupt, with game rules mixed in.
Having it really mimic the Virtue True Faith requires - by ArM5 p.189 True Faith - that they get false Faith points from somewhere determined by the troupe. That would be an up-front decision establishing an important feature of their saga.