Not a unified belief system, but a complex of religious movements that predate Christianity and have roots in both paganism and Judaism. By about the second century AD, Gnostic Christianity had developed and was labelled a heresy by the established church. Distinctive Gnostic beliefs include: two separate divine beings (the unknowable supreme deity and an inferior, evil creator god); the inherent goodness of spirit and evil of matter; the importance of gnosis, or special knowledge, for salvation; and a view of Christ as a messenger of the supreme deity who only appeared to take on a body. Major Gnostic teachers include Valentinus, Basilides, and Marcion.