First Council of Nicaea
325 AD
📂 CHURCH
📖 About This Event
The First Council of Nicaea (325 AD), convened by Emperor Constantine I, was the first Ecumenical Council of the Church and addressed the Arian heresy. Arius, a priest of Alexandria, taught that the Son of God was a created being—'there was a time when He was not'—and therefore not truly divine. This teaching threatened the very heart of Christian faith: if Christ is not truly God, then salvation through Him is impossible.
The council, attended by approximately 318 bishops from throughout the Christian world, produced the Nicene Creed, which affirmed that the Son is 'of one substance (homoousios) with the Father'—fully divine, co-eternal, and co-equal with the Father. The council condemned Arius and his teachings, exiled him, and established the Nicene Creed as the standard of orthodox Christian belief. The council also set the date for Easter, established church canons, and recognized the primacy of the sees of Rome, Alexandria, and Antioch.
The Nicene Creed, revised at the Council of Constantinople (381 AD), remains the primary statement of Christian faith recited at every Catholic Mass. The Catholic Church considers the First Council of Nicaea one of the most important events in Church history. Key Scripture: John 1:1-14; John 10:30; John 14:9; Colossians 1:15-20; CCC 190-196, 247, 255
📜 Key Facts
Date
325 AD
Category
Church
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