One of Irenaeus’s main points throughout his writings, that he makes again and again, is that the one God, the Maker of all things, the Almighty, is the Father of the Lord Jesus Christ. The one God and the Father are the exact same person; just as much as the Son is the Son of the Father, so He is the Son of the one God; just as the Son is not the Father, He is not the one God. In the face of the old gnosticism, this was an important point to stress; the prominent heresies of his day denied the identity of the Father and the one God, just as the prominent heresy of our day does as well.
The below quote from Irenaeus, is, to this author, quite striking:
“Wherefore I do also call upon you, Lord God of Abraham, and God of Isaac, and God of Jacob and Israel, who is the Father of our Lord Jesus Christ, the God who, through the abundance of Your mercy, has had a favour towards us, that we should know You, who has made heaven and earth, who rule over all, who is the only and the true God, above whom there is none other God; grant, by our Lord Jesus Christ, the governing power of the Holy Spirit; give to every reader of this book to know You, that You are God alone, to be strengthened in You, and to avoid every heretical, and godless, and impious doctrine.” (Irenaeus, Against Heresies, Book 3, Ch 6.)
A question well worth asking is, do you worship the same God Irenaeus here prayed to? Can you pray to the one God as the Father of the Son, and speak of Him granting you the grace of the Holy Spirit through His Son? Or have you been led astray into confusion by false teachers, who make the Father, Son, and Spirit out to be one and the same person, the same one God? Is the person you pray to the same person the early church prayed to, or one they did not know? If the whole Trinity, Father, Son, and Spirit, is the one God to which you pray, then who will you have to intercede for you? Who will mediate between you and the one to whom you pray, if Christ, the one mediator between God and man, is the very same person you need a mediator by whom to approach? Who will sanctify you to approach the one God, Who will help your weakness in prayer, and intercede for you with deep groanings, if the Holy Spirit is the one you approach in need of such intercession and groanings?