Credo: The Game of Duelling Dogmas

From BoardGameGeek:

Credo is a strategic negotiation and voting game for 3-6 players set during the formative centuries of early Christianity. Players lead competing Church factions, attempting to expand their influence by converting followers, shaping doctrine, gaining political support, and influencing the creation of the Creed itself. Through alliances, negotiation, and political maneuvering, players compete to ensure their beliefs become accepted doctrine while undermining rival factions. The game combines highly interactive gameplay with a historically inspired setting spanning AD 312-614. -description from the publisher