The words, “All things were made by Him,” are not a proof that the Holy Spirit is included among all things, since He was not made. For otherwise it could be proved by other passages that the Son, and even the Father Himself, must be numbered among all things, which would be similar irreverence.
27. This seems, gracious Emperor, to be a full account of our right feeling, but to the impious it does not seem so. Observe what they are striving after. For the heretics are wont to say that the Holy Spirit is to be reckoned among all things, because it is written of God the Son: “All things were made by Him.”
28. How utterly confused is a course of argument which does not hold to the truth, and is involved in an inverted order of statements. For this argument would be of value for the statement that the Holy Spirit is among all things, if they proved that He was made. For Scripture says that all things which were made were made by the Son; but since we are not taught that the Holy Spirit was made, He certainly cannot be proved to be among all things Who was neither made as all things are, nor created. To me this testimony is of use for establishing each point; firstly, that He is proved to be above all things, because He was not made; and secondly, that because He is above all things, He is seen not to have been made, and is not to be numbered among those things which were made.
29. But if any one, because the Evangelist stated that all things were made by the Word, making no exception of the Holy Spirit (although the Spirit of God speaking in John said: “All things were made by Him,” and said not we were all things which were made; while the Lord Himself distinctly showed that the Spirit of God spoke in the Evangelists, saying, “For it will not be you that speak, but the Spirit of your Father that speaks in you”), yet if any one, as I said, does not except the Holy Spirit in this place, but numbers Him among all, he consequently does not except the Son of God in that passage where the Apostle says: “Yet to us there is one God the Father, of Whom are all things, and we by Him.” But that he may know that the Son is not among all things, let him read what follows, for when he says: “And one Lord Jesus Christ, by Whom are all things,” he certainly excepts the Son of God from all, who also excepted the Father.
30. But it is equal irreverence to detract from the dignity of the Father, or the Son, or the Holy Spirit. For he believes not in the Father who does not believe in the Son, nor does he believe in the Son of God who does not believe in the Spirit, nor can faith stand without the rule of truth. For he who has begun to deny the oneness of power in the Father and the Son and the Holy Spirit certainly cannot prove his divided faith in points where there is no division. So, then, since complete piety is to believe rightly, so complete impiety is to believe wrongly.
31. Therefore they who think that the Holy Spirit ought to be numbered among all things, because they read that all things were made by the Son, must needs also think that the Son is to be numbered among all things, because they read: “All things are of God.” But, consequently, they also do not separate the Father from all things, who do not separate the Son from all creatures, since, as all things are of the Father, so, too, all things are by the Son. And the Apostle, because of his foresight in the Spirit, used this very expression, lest he should seem to the impious who had heard that the Son had said, “That which My Father has given Me is greater than all,” to have included the Son among all.
Source: On the Holy Spirit (New Advent)