Manichaean teaching rests on a radical, cosmic dualism: two eternal, uncreated principles stand in absolute opposition, Light and Darkness, Good and Evil. The Realm of Light is identified with God, spirit, knowledge, truth, and the immortal, while the Realm of Darkness is linked with matter, ignorance, chaos, and demonic forces. These are not merely symbolic categories but metaphysical realities, each with its own domain and character. The material world is understood as the result of a primordial clash in which Darkness invaded the Realm of Light, leading to a tragic mixture in which particles of Light became entangled in matter. From this perspective, history itself becomes the unfolding drama of this conflict, as Light and Darkness contend without the possibility of mutual annihilation or final reconciliation. The ultimate religious vision is one of restoring the original purity of these two realms through their complete separation.

Within this cosmology, human beings are seen as a microcosm of the cosmic struggle. Each person contains a divine spark or inner light that truly belongs to the Realm of Light, yet this soul is imprisoned in a material body that is aligned with Darkness. Human life is therefore marked by an inner tension between spiritual aspiration and material bondage, between truth and ignorance. Ethical and spiritual practice aims at siding with Light in thought, word, and deed, since every action is understood to align either with Light or with Darkness, leaving no neutral ground. Ascetic discipline, right knowledge, and a life ordered toward spiritual purity are valued as means by which the light within can gradually be disentangled from its material prison. Salvation, in this vision, is nothing less than the liberation and return of these scattered light-particles to their proper home in the Realm of Light, bringing the long cosmic struggle closer to its final separation of Good and Evil.