23. For I am aware that the Son of God is revealed under the title Spirit of God in order that we may understand the presence of the Father in Him, and that the term Spirit of God may be employed to indicate Either, and that this is shown not only on the authority of prophets but of evangelists also, when it is said, The Spirit of the Lord is upon Me; therefore He has anointed Me. Luke 4:18 And again, Behold My Servant Whom I have chosen, My beloved in Whom My soul is well pleased, I will put My Spirit upon Him. Matthew 12:18 And when the Lord Himself bears witness of Himself, But if I in the Spirit of God cast out devils, then has the kingdom of God come upon you. For the passages seem without any doubt to denote either Father or Son, while they yet manifest the excellence of nature.
24. For I think that the expression 'Spirit of God' was used with respect to Each, lest we should believe that the Son was present in the Father or the Father in the Son in a merely corporeal manner, that is, lest God might be thought to abide in one position and exist nowhere else apart from Himself. For a man or any other thing like him, when he is in one place, cannot be in another, because what is in one place is confined to the place where it is: his nature cannot allow him to be everywhere when he exists in some one position. But God is a living Force, of infinite power, present everywhere and nowhere absent, and manifests His whole self through His own, and signifies that His own are naught else than Himself, so that where they are He may be understood to be Himself. Yet we must not think that, after a corporeal fashion, when He is in one place He ceases to be everywhere, for through His own things He is still present in all places, while the things which are His are none other than His own self. Now these things have been said to make us understand what is meant by 'nature.'
25. Now I think that it ought to be clearly understood that God the Father is denoted by the Spirit of God, because our Lord Jesus Christ declared that the Spirit of the Lord was upon Him since He anoints Him and sends Him to preach the Gospel. For in Him is made manifest the excellence of the Father's nature, disclosing that the Son partakes of His nature even when born in the flesh through the mystery of this spiritual unction, since after the birth ratified in His baptism this intimation of His inherent Sonship was heard as a voice bore witness from Heaven:— You are My Son; this day have I begotten You. For not even He Himself can be understood as resting upon Himself or coming to Himself from Heaven, or as bestowing on Himself the title of Son: but all this demonstration was for our faith, in order that under the mystery of a complete and true birth we should recognise that the unity of the nature dwells in the Son Who had begun to be also man. We have thus found that in the Spirit of God the Father is designated; but we understand that the Son is indicated in the same way, when He says: But if I in the Spirit of God cast out devils, then has the kingdom of God come upon you. That is, He shows clearly that He, by the power of His nature, casts out devils, which cannot be cast out save by the Spirit of God. The phrase 'Spirit of God' denotes also the Paraclete Spirit, and that not only on the testimony of prophets but also of apostles, when it is said:— This is that which was spoken through the Prophet, It shall come to pass on the last day, says the Lord, I will pour out of My Spirit upon all flesh, and their sons and their daughters shall prophesy. Acts 2:16-17 And we learn that all this prophecy was fulfilled in the case of the Apostles, when, after the sending of the Holy Spirit, they all spoke with the tongues of the Gentiles.
26. Now we have of necessity set these things forth with this object, that in whatever direction the deception of heretics betakes itself, it might yet be kept in check by the boundaries and limits of the gospel truth. For Christ dwells in us, and where Christ dwells God dwells. And when the Spirit of Christ dwells in us, this indwelling means not that any other Spirit dwells in us than the Spirit of God. But if it is understood that Christ dwells in us through the Holy Spirit, we must yet recognise this Spirit of God as also the Spirit of Christ. And since the nature dwells in us as the nature of one substantive Being, we must regard the nature of the Son as identical with that of the Father, since the Holy Spirit Who is both the Spirit of Christ and the Spirit of God is proved to be a Being of one nature. I ask now, therefore, how can They fail to be one by nature? The Spirit of Truth proceeds from the Father, He is sent by the Son and receives from the Son. But all things that the Father has are the Son's, and for this cause He Who receives from Him is the Spirit of God but at the same time the Spirit of Christ. The Spirit is a Being of the nature of the Son but the same Being is of the nature of the Father. He is the Spirit of Him Who raised Christ from the dead; but this is no other than the Spirit of Christ Who was so raised. The nature of Christ and of God must differ in some respect so as not to be the same, if it can be shown that the Spirit which is of God is not the Spirit of Christ also.
27. But you, heretic, as you wildly rave and are driven about by the Spirit of your deadly doctrine the Apostle seizes and constrains, establishing Christ for us as the foundation of our faith, being well aware also of that saying of our Lord, If a man love Me, he will also keep My word; and My Father will love him, and We will come unto him, and make Our abode with him. John 14:23 For by this He testified that while the Spirit of Christ abides in us the Spirit of God abides in us, and that the Spirit of Him that was raised from the dead differs not from the Spirit of Him that raised Him from the dead. For they come and dwell in us: and I ask whether they will come as aliens associated together and make Their abode, or in unity of nature? Nay, the teacher of the Gentiles contends that it is not two Spirits — the Spirits of God and of Christ — that are present in those who believe, but the Spirit of Christ which is also the Spirit of God. This is no joint indwelling, it is one indwelling: yet an indwelling under the mysterious semblance of a joint indwelling, for it is not the case that two Spirits indwell, nor is one that indwells different from the other. For there is in us the Spirit of God and there is also in us the Spirit of Christ, and when the Spirit of Christ is in us there is also in us the Spirit of God. And so since what is of God is also of Christ, and what is of Christ is also of God, Christ cannot be anything different from what God is. Christ, therefore, is God, one Spirit with God.
28. Now the Apostle asserts that those words in the Gospel, I and the Father are one John 10:30, imply unity of nature and not a solitary single Being, as he writes to the Corinthians, Wherefore I give you to understand, that no man in the Spirit of God calls Jesus anathema. 1 Corinthians 12:3 Do you now perceive, O heretic, in what spirit you call Christ a creature? For since they are under a curse who have served the creature more than the Creator — in affirming Christ to be a creature, learn what you are, since you know full well that the worship of the creature is accursed. And observe what follows, And no one can call Jesus Lord, but in the Holy Spirit. 1 Corinthians 12:3 Do you perceive what is lacking to you, when you deny Christ what is His own? If you hold that Christ is Lord through His Divine nature, you have the Holy Spirit. But if He be Lord merely by a name of adoption you lack the Holy Spirit, and are animated by a spirit of error: because no one can call Jesus Lord, but in the Holy Spirit. But when you say that He is a creature rather than God, although you style Him Lord, still you do not say that He is the Lord. For to you He is Lord as one of a common class and by a familiar name, rather than by nature. Yet learn from Paul His nature.