They believed that all human beings contained within them an element of the Divine Light trapped in bodies of Matter by "the Prince of this world", Satan (cf Gospel of John) who had created the material universe as a consequence of his rebellion against God.
According to their beliefs, humans harbor an inner light of divinity encased in mortal bodies, which was placed there by Satan, the adversary, following his rebellion against the Almighty, as described in the Gospel of John.