3rd century
Manichaeism
Reality is a cosmic battle between eternal principles of light/good/spirit and darkness/evil/matter.
The Central Error
Its radical dualism treats matter as evil and salvation as escape from material existence.
Historic Response
Opposed by Christian theologians, including Augustine after his conversion from Manichaeism; it is more accurately a distinct religion than a Christian sect.
Modern Echoes
Treating the body, marriage, food, creation, or material life as inherently evil instead of created good yet fallen.