We have received baptism for the remission of sins, in the name of God the Father, and in the name of Jesus Christ, the Son of God, who was incarnate and died and rose again, and in the Holy Spirit of God.
And this baptism is the seal of eternal life, and is the new birth unto God, that we should no longer be the sons of mortal men, but of the eternal and perpetual God; and that what is everlasting and continuing is made God.
[…] It is necessary that things that are made should have the beginning of their making from some great cause; and the beginning of all things is God. For He Himself was not made by any, and by Him all things were made.
And therefore it is right first of all to believe that there is One God, the Father, who made and fashioned all things, and made what was not that it should be, and who, containing all things, alone is uncontained.
Now among all things is this world of ours, and in the world is man: so then this world also was formed by God.
Thus then there is shown forth One God, the Father, not made, invisible, creator of all things; above whom there is no other God, and after whom there is no other God (cf. Isaiah 43:10).
And, since God is rational, therefore by (the) Word He created the things that were made; and God is Spirit, and by (the) Spirit He adorned all things: as also the prophet says: By the word of the Lord were the heavens established, and by his spirit all their power Psalm 32/33:6).
Since then the Word establishes, that is to say, gives body and grants the reality of being, and the Spirit gives order and form to the diversity of the powers; rightly and fittingly is the Word called the Son, and the Spirit the Wisdom of God.
Well also does Paul His apostle say: One God, the Father, who is over all and through all and in us all (Eph. 4:6).
For over all is the Father; and through all is the Son, for through Him all things were made by the Father; and in us all is the Spirit, who cries Abba Father (cf. Gal. 4:6), and fashions man into the likeness of God.
Now the Spirit shows forth the Word, and therefore the prophets announced the Son of God; and the Word utters the Spirit, and therefore is Himself the announcer of the prophets, and leads and draws man to the Father.
Irenaeus of Lyons (2nd century AD – c. 202): Demonstration of the Apostolic Preaching, 3-5.