Have you ever heard a blasphemy more insidious? Has anyone fallen so conspicuously in the inescapable judgment for having blasphemed against the Holy Spirit? Only Montanus raged to such an extent against the Spirit, insulting him with lowly names and disparaging his nature to such and extent that he said that the Spirit brought ignominy on the one who had made him. Eunomius should have avoided speaking in a lowly manner about the Spirit to keep from deflating his own self-importance. We will speak of this when we have the time.
Isn’t it clear to everyone that no activity of the Son is severed from the Father? That none of all the existing things that belong to the Son is foreign to the Father? For he says: All that is mine is yours, and all that is yours is mine (John 17.10). So, then, how does Eunomius impute the cause of the Spirit as an accusation against the Only-Begotten’s nature? If he says these things to introduce two principles in conflict with one another, he will be crushed along with Mani and Marcion. But if he makes the beings depend on a single principle, that which is said to come into being from the Son has a relationship with the first cause. Hence, even if we believe that all things have been brought into being through God the Word, we nevertheless do not deny that the God of the universe is the cause of all.
How is it not an unmistakable danger to separate the Spirit from God? On the one hand, the Apostle hands down to us that they are connected, saying now that he is the Spirit of Christ, now that he is the Spirit of God. For he writes: If anyone does not have the Spirit of Christ, he does not belong to him (Rom. 8.9). And again: You have not received the spirit of the world, but the spirit that comes from God (1Cor. 2.12). On the other hand, the Lord says that he is the Spirit of Truth (John 15.26)—since he himself is the Truth—and that he proceeds from the Father (John 15.26). But Eunomius, in order to diminish the glory of our Lord Jesus Christ, separates the Spirit from the Father and imputes him exclusively to the Only-Begotten in order to diminish his glory, insulting him (or so he thinks) without any anticipation of the recompense for his wicked words and ideas on the day of retribution.