“The coupling of masculine and feminine potencies in the upper world, which subsequently came to play such a significant role in the doctrines of the Spanish kabbalists, seems also to have been known in Cathar circles. Here too we should assume a common source in the ancient gnosis rather than immediate influences. However, it is plausible that some details were taken over by the Cathars from Jewish mystics as, for example, the idea, well known to us from the Hekhaloth texts, that Israel was the name of a celestial angel.
Such ideas may also have been introduced into the movement by Jews who attached themselves to the Cathars. Thus, we learn for example that at the end of the twelfth century, a weaver named Johannes Judaeus stood at the head of the Italian Cathars as their bishop. The name would suggest, though it by no means proves, Jewish origin. The surname Judaeus does not always signify Jewish lineage in the Middle Ages.
Another angelological doctrine to be found only among the Cathars and in the kabbalistic traditions of Moses de Leon and the Zohar asserts that the prophet Elijah was an angel descended from heaven. The ideas of the two groups resembled one another, here and there, on the subject of the soul’s fate in the terrestrial paradise and its entry into the celestial paradise after the last judgment, and regarding the garments worn by the souls before their birth that are then preserved in heaven during their earthly existence. But all of these are disparate, and unconnected details, and they concern points of secondary interest only.
As regards the fundamental conceptions, there could of course be no real agreement between the two movements, since in their rejection of the world as the creation of Satan and of the Torah as the law of Satan, the Cathars go much further in their metaphysical anti-Semitism than does the Catholic Church. Besides, the Jewish scholars of Provence were thoroughly conscious of the gulf separating the Jewish conception of the world from that of the Cathars.”
Gershom Scholem, Origins of the Kabbalah, pp. 236-7.