The Ecumenical Christian Creeds
The council of Nicea (325 AD) was called by Constantine, the first Christian emperor, in order to respond to the Arian controversy. Arius, a presbyter in Alexandria, Egypt, denied the equal divinity of the Son of God and instead taught that he was God the Father’s first and most perfect creature. In his own words, “there was a time when [the Son] was not.” Nicea, with its creed, countered this false teaching by asserting that the Son was and is co-eternal with the Father - that is to say, “one in being” (homoousios) with the Father.
Convened by Emperor Marcian, the council of Chalcedon (451 AD) dealt with Christological debates that took place after Nicea; specifically, the council sought to expound on the hypostatic union of Christ, i.e., the union of the divine nature and human nature in the one person (hypostasis) of Christ. The Chalcedonian “definition” or creed teaches that Christ is “truly God and truly man,” and yet the two natures are “without confusion, without change, without division, [and] without separation.”
Though not written by Athanasius, this creed is forever named after him because of his defense of orthodoxy and deep theological insights into the mystery of the Trinity. The Athanasian creed attempted to clarify some of the complexities of this doctrine for the purpose of preserving and advancing the “catholic faith.” In it we read that there is “one eternal being,” consisting of three (distinct) persons. These three are co-eternal and co-equal as God and Lord.