Manichaeism
Manichaeism was a major Gnostic religion that was founded by the Iranian prophet Mani (c. 216–276 AD) in the Sasanian Empire. Manichaeism taught an elaborate dualistic cosmology describing the struggle between a good, spiritual world of light, and an evil, material world of darkness. Through an ongoing process which takes place in human history, light is gradually removed from the world of matter and returned to the world of light whence it came. Its beliefs were based on local Mesopotamian gnostic and religious movements.
Manichaeism thrived between the third and seventh centuries, and at its height was one of the most widespread religions in the world. Manichaean churches and scriptures existed as far east as China and as far west as the Roman Empire. It was briefly the main rival to Christianity in the competition to replace classical paganism. Manichaeism survived longer in the East than in the West, and it appears to have finally faded away after the 14th century in southern China, contemporary to the decline in China of the Church of the East. While most of Mani’s original writings have been lost, numerous translations and fragmentary texts have survived.
Until discoveries in the 1900s of original sources, the only sources for Manichaeism were descriptions and quotations from non-Manichaean authors, either Christian, Muslim, Buddhist or Zoroastrian. While often criticizing Manichaeism, they also quoted directly from Manichaean scriptures. This enabled Isaac de Beausobre, writing in the 18th century, to create a comprehensive work on Manichaeism, relying solely on anti-Manichaean sources.