Chapter 3.
49 If the Son is above all, through Whom our salvation received its commencement, so that it might be preached, certainly God the Father also, Who testifies and gives confirmation concerning our salvation by signs and wonders, is excepted from all. In like manner the Spirit, Who bears witness to our salvation by His diversities of gifts, is not to be numbered with the crowd of creatures, but to be reckoned with the Father and the Son; Who, when He divides, is not Himself divided by cutting off Himself, for being indivisible He loses nothing when He gives to all, as also the Son, when the Father receives the kingdom, loses nothing, nor does the Father, when He gives that which is His to the Son, suffer loss. We know, then, by the testimony of the Son that there is no loss in the division of spiritual grace; for He Who breathes where He wills is everywhere free from loss. Concerning which power we shall speak more fully farther on.
50. In the meanwhile, since our intention is to prove in due order that the Spirit is not to be reckoned among all things, let us take the Apostle, whose words they call in question, as an authority for this position. For what “all things” would be, whether visible or invisible, he himself declared when he said: “For in Him were all things created in the heavens and in earth.” You see that “all things” is spoken of things in the heavens, and of things in earth, for in the heavens are also invisible things which were made.
51. But that no one should be ignorant of this he added those of whom he was speaking: “Whether thrones or dominions or principalities or powers, all things were created by Him and in Him, and He is before all, and in Him all things consist.” Does he, then, include the Holy Spirit here among creatures? Or when he says that the Son of God is before all things, is he to be supposed to have said that He is before the Father? Certainly not; for as here he says that all things were created by the Son, and that all things in the heavens consist in Him, so, too, it cannot be doubted that all things in the heavens have their strength in the Holy Spirit, since we read: “By the word of the Lord were the heavens established and all the strength of them by the Spirit of His mouth.” He, then, is above all, from Whom is all the strength of things in heaven and things on earth. He, then, Who is above all things certainly does not serve; He Who serves not is free; He Who is free has the prerogative of lordship.
52. If I were to say this at first it would be denied. But in the same manner as they deny the less that the greater may not be believed, so let us set forth lesser matters first that either they may show their perfidy in lesser matters, or, if they grant the lesser matters, we may infer greater from the lesser.
53. I think, most merciful Emperor, that they are most fully confuted who dare to reckon the Holy Spirit among all things. But that they may know that they are pressed not only by the testimony of the apostles, but also by that of our Lord; how can they dare to reckon the Holy Spirit among all things, since the Lord Himself said: “He who shall blaspheme against the Son of Man, it shall be forgiven him; but he who shall blaspheme against the Holy Ghost shall never be forgiven, either here or hereafter.” How, then, can any one dare to reckon the Holy Spirit among creatures? Or who will so blind himself as to think that if he have injured any creature he cannot be forgiven in any wise? For if the Jews because they worshipped the host of heaven were deprived of divine protection, while he who worships and confesses the Holy Spirit is accepted of God, but he who confesses Him not is convicted of sacrilege without forgiveness: certainly it follows from this that the Holy Spirit cannot be reckoned among all things, but that He is above all things, an offense against Whom is avenged by eternal punishment.
54. But observe carefully why the Lord said: “He who shall blaspheme against the Son of Man it shall be forgiven him, but he who shall blaspheme against the Holy Ghost shall never be forgiven, either here or hereafter.” Is an offense against the Son different from one against the Holy Spirit? For as their dignity is one, and common to both, so too is the offense. But if any one, led astray by the visible human body, should think somewhat more remissly than is fitting concerning the Body of Christ (for it ought not to appear of little worth to us, seeing it is the palace of chastity, and the fruit of the Virgin), he incurs guilt, but he is not shut out from pardon, which he may attain to by faith. But if any one should deny the dignity, majesty, and eternal power of the Holy Spirit, and should think that devils are cast out not in the Spirit of God, but in Beelzebub, there can be no attaining of pardon there where is the fullness of sacrilege; for he who has denied the Spirit has denied also the Father and the Son, since the same is the Spirit of God Who is the Spirit of Christ.
Source: On the Holy Spirit (New Advent)