Generosity is waaaaay strong. I find it to be the only commandment I can regularly beat Impossible difficulty. What makes it so strong is that there are two very strong developments: Patron Saint (Art side) and Grow Together (Commune side). WIth patron saint you'll have stupidly good new disciples (lategame my disciples were consistently having 25-30 charisma BEFORE EVEN PICKING A CLASS), and with Grow together you'll swim in Ability Points (making your attacks devastating). No other commandments have such powerful developments.