Athanasius was present at the Council of Nicea. Following that council, the Church continued to wrestle with Arianism. The Athanasian Creed was written towards the end of the 5th Century, about 100 years after Athansius died. It may have been written by his followers and was a response to issues regarding Jesus’ divinity and humanity. It also addresses the mystery of the Trinity.
Unlike the Apostles’ and Nicene Creeds, the Athanasian Creed is not written with three distinct sections which lay out specifics for God the Father, the Son, and the Holy Spirit. The first portion of the creed speaks to all three persons of the Trinity, their uniqueness, inter-relatedness, and their differences. The second portion of the creed speaks to Jesus and his work in securing our salvation.
Traditionally the Athanasian Creed is spoken on Holy Trinity Sunday, which is the Sunday following Pentecost.
Whoever will be saved shall, above all else, hold the catholic faith.
Which faith, except everyone keeps whole and undefiled, without doubt he will perish eternally.
And the catholic faith is this: that we worship one God in three persons and three persons in one God, neither confusing the persons nor dividing the substance.
For there is one person of the Father, another of the Son, and another of the Holy Spirit.
But the Godhead of the Father, of the Son, and of the Holy Spirit is all one: the glory equal, the majesty coeternal.
Such as the Father is, such is the Son, and such is the Holy Spirit.
The Father uncreated, the Son uncreated, and the Holy Spirit uncreated.
The Father incomprehensible, the Son incomprehensible, and the Holy Spirit incomprehensible.
The Father eternal, the Son eternal, and the Holy Spirit eternal.
And yet there are not three eternals but one eternal.
As there are not three uncreated nor three incomprehensibles but one uncreated and one incomprehensible.
So likewise the Father is almighty, the Son almighty, and the Holy Spirit almighty. And yet they are not three almighties but one almighty.
So the Father is God, the Son is God, and the Holy Spirit is God. And yet they are not three Gods but one God.
So likewise the Father is Lord, the Son Lord, and the Holy Spirit Lord. And yet they are not three Lords but one Lord.
For as we are compelled by the Christian truth to acknowledge every person by himself to be both God and Lord,
So we cannot by the catholic faith say that there are three Gods or three Lords.
The Father is made of none, neither created nor begotten. The Son is of the Father alone, not made nor created but begotten.
The Holy Spirit is of the Father and of the Son, neither made nor created nor begotten but proceeding.
So there is one Father, not three Fathers; one Son, not three Sons; one Holy Spirit, not three Holy Spirits.
And in this Trinity none is before or after another; none is greater or less than another; but the whole three persons are coeternal together and coequal, so that in all things, as has been said, the Unity in Trinity and the Trinity in Unity is to be worshiped.
He, therefore, that will be saved is compelled thus to think of the Trinity.
Furthermore, it is necessary to everlasting salvation that he also believe faithfully the incarnation of our Lord Jesus Christ.
For the right faith is that we believe and confess that our Lord Jesus Christ, the Son of God, is God and man; God of the substance of the Father, begotten before all worlds; and man of the substance of his mother, born in the world; Perfect God and perfect man, of a reasonable soul and human flesh subsisting.
Equal to the Father as touching his Godhead and inferior to the Father as touching his manhood; Who, although he is God and man, yet he is not two but one Christ:
One, not by conversion of the Godhead into flesh but by taking the manhood into God:
One altogether, not by confusion of substance but by unity of person.
For as the reasonable soul and flesh is one man, so God and man is one Christ; Who suffered for our salvation, descended into hell, rose again the third day from the dead.
He ascended into heaven, he sits at the right hand of the Father, God Almighty, from whence he will come to judge the living and the dead.
At whose coming all men will rise again with their bodies and will give an account of their own works.
And they that have done good will go into life everlasting; and they that have done evil, into everlasting fire.
This is the catholic faith which, except a man believe faithfully and firmly, he cannot be saved.