MONARCHIANISM Before considering the specific controversies that gave rise to the great conciliar decisions concerning God and Christ, it is necessary to say something about what some theologians would describe as the outstanding heresy of the third-century, namely Monarchianism. It was “in general, an attempt to stress monotheism [Tertullian: “the monarchy of the one God”] against those who would make Jesus Christ, as the incarnation of the Logos, a second God, or [when the action of the Holy Spirit