The Ecumenical Councils and Creeds

The Ecumenical Councils and Creeds

The first five centuries of Christianity were marked by intense theological debate about the nature of God, the person of Christ, and the relationship between the divine and the human. These debates were resolved — or at least formally settled — by a series of ecumenical councils: gatherings of bishops from across the Christian world that defined orthodox doctrine and condemned heresy. The creeds produced by these councils remain foundational statements of Christian belief to this day.

The Arian Controversy

The most significant theological crisis of the early Church was the Arian controversy. Arius (c. AD 256–336), a priest in Alexandria, taught that the Son of God (the Logos, or Word) was a created being — the first and greatest of God’s creatures, but not eternal and not truly God. Arius argued:

• There was a time when the Son did not exist — ‘there was when he was not’
• The Son was created by the Father out of nothing (ex nihilo)
• The Son is of a different substance (heteroousios) from the Father
• The Son is divine in a subordinate, derivative sense — divine by grace, not by nature