In the days of the Nicean Council, during the Arian Christological controversy that rocked the early church, the absence of a single Greek letter made a great deal of difference. Per the formulation that later became the Nicene Creed, God the Father was understood to be of the same (homoousios) essence as God the Son, not merely similar (homoiousios). This doctrine continues to govern Christological thought today, and forms an essential component of a proper