The antipathy between mages and priests can be turned off. This has the following effects:
Stacks containing priests do not receive a combat attack bonus against stacks containing a magician or undead.
Bless Follower can be used on nobles possessing undead.
The Staff of the Sun is not in play.
Magicians in a province do not prevent peasants from making offerings at temples.
Priests do not receive a piety bonus for performing Last Rites on a magician.
Magicians do not receive an aura bonus for eating the body of a priest.
Priests and magicians may stack together.