1. ニカイア信条の語法を作成し、アリウス主義の異教を非難した325年の最初の全教会会議(the first ecumenical council in 325 which produced the wording of the Nicene Creed and condemned the heresy of Arianism)
2. 偶像破壊主義に意義を唱え、神聖なイメージの崇拝を規制した787年の7回目の全教会会議(the seventh ecumenical council in 787 which refuted iconoclasm and regulated the veneration of holy images)