Due to Mani's organizational abilities, the simplicity of his dualistic theology, and his incorporation of elements from other religions, Manichaeism spread rapidly, and it was soon disseminated throughout the Roman Empire and into China.Beliefs
Basic to the religion's doctrine was the conflicting dualism between the realm of God, represented by light and by spiritual enlightenment, and the realm of Satan, symbolized by darkness and by the world of material things. To account for the existence of evil in a world created by God, Mani posited a primal struggle in which the forces of Satan separated from God; humanity, composed of matter, that which belongs to Satan, but infused with a modicum of godly light, was a product of this struggle, and was a paradigm of the eternal war between the forces of light and those of darkness. Christ, the ideal, light-clad soul, could redeem for each person that portion of light God had allotted. Light and dark were seen to be commingled in our present age as good and evil, but in the last days each would return to its proper, separate realm, as they were in the beginning. The Christian notion of the Fall and of personal sin was repugnant to the Manichees; they felt that the soul suffered not from a weak and corrupt will but from contact with matter. Evil was a physical, not a moral, thing; a person's misfortunes were miseries, not sins.
Mani's followers were divided into two classes: the elect, or perfect, were assured of immediate felicity after death because of the resource of light they had acquired through strict celibacy, austerity, teaching, and preaching; and the auditors, or hearers, the laity who administered to the elect, and who could marry. Believing in metempsychosis (see transmigration of souls), the auditors hoped to be reborn as elect. All other were sinners, doomed to hell.
Several Christian emperors, including Justinian, published edicts against the Manichees. St. Augustine, in his youth a Manichee, describes in his Confessions his conversion to Christianity. Little is heard of the Manichees in the West after the 6th cent., but their doctrines reappear in the medieval heresies of the Cathari, Albigenses, and Bogomils. It was the practice in the Middle Ages to call by the name of Manichaeism any dualist Christian heresy. The young religion of Islam was also challenged by the Manichean sect in Africa and Asia. The sect survived in the East, notably in Chinese Turkistan (Xinjiang), until about the 13th cent.