Just reading Cults of Prax. It says that every Praxian can be said to be a member of Eiritha as a Lay member. This makes sense, but then the prohibited magic is quite extensive and would prevent one being a successful warrior or hunter for example. Personally I'd ignore that bit, but what do other folk think?
Prohibited: Bladesharp, Bludgeon, Disruption, Fanaticism, Fireblade, Fire Arrow, Iron Hand, Multimissile, Speedart.
Restricted (2x normal): all non-axe weapons skills and all knowledge skills.