The Council of Nicea (or Nicaea; Greek Nikaia) was Christianity's first ecumenical council. It was called by Emperor Constantine in 325 CE to secure for the first time theological cohesion among the churches, especially regarding Christology and ritual practice. There were approximately 250 ranking attendees to debate and decide the future direction of Christianity.

A creed of faith was determined, imposing a single theology on all Christians. The main debate in the council centered on the Christological Arian controversy. The Arians believed that because Christ was the “only begotten” Son of the Father (see the Gospel of John 1:14, 16; 3:16, 18), he was not coeternal with the Father and must necessarily be inferior to Him. They were staunch monotheists and strictly opposed attributing any multiplicity ...