12th century dualist heresy where it is believed that Good and Evil are two gods and that the material world is Evil. But the twist is that to become a Cathar priest you had to become a perfect through a rite called the consolamentum (consolation). But since most Cathars were not perfect but only credentes (believers) they decided to postpone the consolamentum until they were dying. And before this, they lived rather liberal lives for the times. They ate lots of meat and had lots of sex among other things. A laudable approach to dealing with the duality of attending to the spirit while living in the evil world.
Books to note:
Stephen O’Shea. The Perfect Heresy: The Revolutionary Life and Death of the Medieval Cathars.
Jonathan Sumption. The Albigensian Crusade.
Emmanuel Le Roy Ladurie. Montaillou. Translation by Barbara Bray.