The second is that the founder of Manicheanism was Manicheus, who lived in Mesopotamia. Manicheanism assimilated much of the Christian message, re-interpreting it to fit the Gnostic belief system. | The second is that the founder of Manicheanism was Manicheus, who lived in Mesopotamia. Manicheanism assimilated much of the Christian message, re-interpreting it to fit the Gnostic belief system. |