Athanasian Creed (A.D. 500)
This creed is attributed to Athanasius, the fourth century bishop of Alexandria who was the strongest defender of the doctrines of the Trinity and the divinity of Christ. It defines the doctrines of the Trinity and the nature of Christ in very concise language.
Please note that the term "catholic" with the lower case 'c' is not a reference to the Roman Catholic Church, but is a reference to the universal Christian faith, since that is how the term was originally used.
Whosoever will be saved, before all things it is necessary that he hold the catholic 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 Spirit. But the godhead of the Father, of the Son, and of the Holy Spirit, is all one, the glory equal, the majesty co-eternal.
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 they are not three eternals, but one Eternal.
As also there are not three incomprehensibles, nor three uncreated, 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 not three lords, but one Lord.
For as we are compelled by the Christian verity to acknowledge each Person by Himself to be both God and Lord, so we are also forbidden by the catholic religion to 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, 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 the Trinity none