Do what thou wilt shall be the whole of the Law.

O.T.O. also encompasses Ecclesia Gnostica Catholica (E.G.C.), the Gnostic Catholic Church, which was originally brought to O.T.O. by Dr. GĂ©rard Encausse (Papus) in 1908 e.v. The E.G.C. is a Thelemic religious environment, dedicated to the advancement of Light, Life, Love, and Liberty through the Law of Thelema.

The central activity of the E.G.C. is the celebration of the Gnostic Mass, Liber XV, which was composed by Aleister Crowley for O.T.O. in 1913 e.v. Membership in E.G.C. is available through baptism and confirmation.

Members of O.T.O. in good standing are eligible for clerical training and ordination in E.G.C. Many O.T.O. local bodies celebrate the Gnostic Mass on a regular basis.

Love is the law, love under will