Catharism was a self-described Christian movement which incorporated Gnostic and dualistic ideas into its interpretation of Scripture. The terms Cathar, Catharism and even Perfecti and Credentes were ones used by their persecuters, the religious and temporal authorities of the time. The Cathars themselves never referred to themselves as such, calling themselves only "Bons Hommes", "Bonnes Femmes" or "Bons Chrétiens" (i.e. "Good Men", "Good Women" and "Good Christians"). 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. Christ was an emissary of God, sent into this world to help us return to the Father.
Catharism held to a doctrine of reincarnation, the individual soul being born into this world of suffering again and again until it had reached the state of inner purification which meant it could return. It was in this way that the Cathars interpreted the idea of Eternal Life in Jesus Christ. They argued for a return to the essence of Christ's teaching, an embracing of the Apostolic ideal of human behaviour and rejected the established Church as "the Synagogue of Satan" for having turned its back on Christ's message with its vast material power, wealth and corruption.