The Ecclesia Gnostica Catholica is the religious arm of the Ordo Templi Orientis. Baptisms are offered to anyone, but Confirmations and place in the ecclesiastic hierarchy are dependent on degrees held in the O.T.O. The principal ritual of the E.G.C. is the Gnostic Mass, but it also offers rites classically associated with churches, such as marriage, or burial.
A Brief History of the E.G.C.
The Gnostic Church was founded in 1890 by Jules Doinel, a libertarian and Freemason, based on the combined theological doctrines of Simon Magus, Valentinus, and Marcus; with sacraments derived from the Cathars, but conferred in a way very much influenced by Roman Catholicism. Nevertheless, the Church was intended to present a system of mystical Freemasonry. Among one of the first of his appointed bishops was Papus (Gérard Encausse), famous occultist and founder of the Martinist Order. Doinel left the Gnostic Church in 1895, leaving it to the bishops.
Encausse met Theodor Reuss, founder of the O.T.O. in 1908, who gave him a charter to establish a "Supreme Grand Council General of the Unified Rites of Antient and Primitive Masonry for the Grand Orient of France and its Dependencies at Paris.", and Papus named Reuss Primarch of the Gnostic Church - who incorporated it, along with many other groups, into the O.T.O.. Later the same year Papus' branch renamed themselves l'Église Gnostique Universelle (Universal Gnostic Church).
Crowley joined the O.T.O. in 1910, and wrote the Gnostic Mass in 1913. On that document, he used the Latin name Ecclesia Gnostica Catholica. Reuss' acceptance of the rite marked a clear break from the Universal Gnostic Church, and made the E.G.C. a Thelemic church.
The Patriarch of the E.G.C. is always the current Outer Head of the Order of the Ordo Templi Orientis.