Whosoever will be saved, before all things it is necessary that he hold the catholic [i. e., universal, Christian] faith.
Which faith except everyone do keep whole and undefiled, without doubt he shall perish everlastingly.
And the catholic faith is this, that we worship one God in Trinity and Trinity in Unity,
Neither confounding the Persons nor dividing the Substance.
For there is one Person of the Father, another of the Son, and another of the Holy Ghost.
But the Godhead of the Father, of the Son, and of the Holy Ghost is all one: the glory equal, the majesty coeternal.
Such as the Father is, such is the Son, and such is the Holy Ghost.
The Father uncreate, the Son uncreate, and the Holy Ghost uncreate.
The Father incomprehensible, the Son incomprehensible, and the Holy Ghost incomprehensible.
The Father eternal, the Son eternal, and the Holy Ghost eternal.
And yet they 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 Ghost almighty.
And yet they are not three Almighties, but one Almighty.
So the Father is God, the Son is God, and the Holy Ghost is God.
And yet they are not three Gods, but one God.
So likewise the Father is Lord, the Son Lord, and the Holy Ghost Lord.
And yet not three Lords, but one Lord.
For like as we are compelled by the Christian verity to acknowledge every Person by Himself to be God and Lord,
So are we forbidden by the catholic religion to say, There be 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 Ghost 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 Ghost, not three Holy Ghosts.
And in this Trinity none is before or after other; none is greater or less than another;
But the whole three Persons are coeternal together and coequal, so that in all things, as is aforesaid, the Unity in Trinity and the Trinity in Unity is to be worshiped.
He, therefore, that will be saved must thus think of the Trinity. ….
Athanasius of Alexandria
…sometimes referred to as “The Father of Orthodoxy” because of his faithful stand at Nicaea in 325 A.D. for the deity of Jesus Christ. He is not the author of the creed named in his honor but of the Nicene Creed adopted to combat Arianism. The date of the Athanasian Creed is uncertain, though most historians acknowledge it to be of much later origin. —Ed.