He quoted Tertullian's regula fidei from the early second century AD:
[T]he Creator of the world, who produced all things out of nothing through His own Word, first of all sent forth; that this Word is called His Son, and, under the name of God, was seen “in diverse manners” by the patriarchs, heard at all times in the prophets, at last brought down by the Spirit and Power of the Father into the Virgin Mary, was made flesh in her womb, and, being born of her, went forth as Jesus Christ; thenceforth He preached the new law and the new promise of the kingdom of heaven, worked miracles; having been crucified, He rose again the third day; (then) having ascended into the heavens, He sat at the right hand of the Father; sent instead of Himself the Power of the Holy Ghost to lead such as believe; will come with glory to take the saints to the enjoyment of everlasting life and of the heavenly promises, and to condemn the wicked to everlasting fire, after the resurrection of both these classes shall have happened, together with the restoration of their flesh. This rule, as it will be proved, was taught by Christ, and raises amongst ourselves no other questions than those which heresies introduce, and which make men heretics. (Prescriptions Against Heresies).
Michael Bird then attempts a "faithful restatement... in our own contemporary language."
God the Father, the maker of the universe, who, through Word and Spirit, made all things out of nothing, planned all things for the demonstration of his love and the satisfaction of his glory. He created Adam and Eve in his own image and after their rebellion, He also revealed himself as the Lord in diverse ways to the patriarchs, to Israel, and in the prophets, to call to himself a people worthy of his name, among and for the nations. When the time had fully come, He sent his Son, born of a woman and born under the Law, a Son of David, enfleshed as a man in the womb of the Virgin Mary through the Holy Spirit, and who came forth as Jesus of Nazareth. Jesus was baptized and in the power of the Holy Spirit he preached the hope of Israel and the kingdom of God, he proclaimed good news to the poor, did many miraculous deeds, was crucified under Pontius Pilate, he was buried and rose again on the third day according to the scriptures. Then, having made purification for sins, he ascended into the heavens, where he sat down at the right hand of the Father, from where he shall come again in glory to judge both the living and the dead, and after the great resurrection, he shall take his people into the paradise of the new creation, and condemn the wicked to everlasting fate. The church now works in the mission of God, in dependence upon the Father, in the power of the Holy Spirit, bearing testimony to Jesus Christ, to preach good news and to show mercy, until the day when God will be all in all.
Did you spot the difference? What is being said about the Old Testament in these two statements? We go from language of "the Son" being "seen" and "heard" to language of the Father merely "revealing himself as the Lord" in diverse ways.
I'm not even sure the switch of Person was a deliberate decision. (I've asked). I wonder whether the modern theologian is simply blind to what the early church held self-evident: that the Son is the eternal Word through Whom the Father always acts and reveals.
I'm not saying it's rank revisionism, but I am saying it's a revealing shift and one we should try to undo.
The Son is not the best Word - He's the Word. He's not the clearest Image - He's the Image. He's not the Seal of a series of improving revelations. He is the Revelation of God.
Let us indeed get back to such a rule of faith!