Ambrosiaster : He says of the Gentiles who believed in Christ, "You are sons," having previously been enemies. There can be no doubt that believing Jews were also said to be sons of God, since they had long been called by that name. They had received the name of sons at one time as though by anticipation in order that this sonship might subsequently be understood in Christ, being incomplete without the Spirit. — EPISTLE TO THE Galatians 4.6.1 Athanasius of Alexandria : But this is God's kindness to man, that of whom He is Maker, of them according to grace He afterwards becomes Father also; becomes, that is, when men, His creatures, receive into their hearts, as the Apostle says, 'the Spirit of His Son, crying, Abba, Father.' And these are they who, having received the Word, gained power from Him to become sons of God; for they could not become sons, being by nature creatures, otherwise than by receiving the Spirit of the natural and true Son. Wherefore, that this might be, 'The Word became flesh,' that He might make man capable of Godhead. This same meaning may be gained also from the Prophet Malachi, who says, 'Hath not One God created us? Have we not all one Father?' for first he puts 'created,' next 'Father,' to shew, as the other writers, that from the beginning we were creatures by nature, and God is our Creator through the Word; but afterwards we were made sons, and thenceforward God the Creator becomes our Father also. Therefore 'Father' is proper to the Son; and not 'creature,' but 'Son' is proper to the Father. Accordingly this passage also proves, that we are not sons by nature, but the Son who is in us; and again, that God is not our Father by nature, but of that Word in us, in whom and because of whom we 'cry, Abba, Father.' And so in like manner, the Father calls them sons in whomsoever He sees His own Son, and says, 'I begat;' since begetting is significant of a Son, and making is indicative of the works. And thus it is that we are not begotten first, but made; for it is written, 'Let Us make man;' but afterwards, on receiving the grace of the Spirit, we are said thenceforth to be begotten also; just as the great Moses in his Song with an apposite meaning says first 'He bought,' and afterwards 'He begat;' lest, hearing 'He begat,' they might forget their own original nature; but that they might know that from the beginning they are creatures, but when according to grace they are said to be begotten, as sons, still no less than before are men works according to nature. — Four Discourses Against the Arians, Discourse 2, Section 59 Augustine of Hippo : There are two words that he has set down so that the former may be interpreted by the latter, "for Abba" means the same as "Father." Now we see that he has elegantly, and not without reason, put together words from two languages signifying the same thing because of the whole people, which has been called from Jews and Gentiles into the unity of faith. — EPISTLE TO THE Galatians 31 [1B.4.6] Gaius Marius Victorinus : Behold the whole array of those three powers through one power and one Godhead. For God, he says, who is the Father, sent his own Son, who is Christ, and again Christ, who himself being the power of God is God, … sent the spirit of his Son, who is the Holy Spirit. — EPISTLE TO THE Galatians 2.4.6 Jerome : (Verse 6.) But because you are sons of God, God has sent the spirit of His Son into our hearts, crying out, Abba, Father. Clearly the Apostle Paul mentions three spirits, the Spirit of the Son of God, as in this present place, God has sent the Spirit of His Son into our hearts (Rom. VIII, 14). And the Spirit of God, as in that place: For as many as are led by the Spirit of God, these are sons of God. And the Holy Spirit, as in that place: Your bodies are the temple of the Holy Spirit, who is in you (I Cor. VI, 19). That the Holy Spirit is distinct from the Son of God is clearly and convincingly confirmed in the Gospel: Whoever speaks a word against the Son of man will be forgiven. But whoever speaks against the Holy Spirit, neither in this age nor in the age to come will be forgiven (Luke 12:10). This is because many, due to their lack of knowledge of the Scriptures (as Firmianus also states in the eighth letter to Demetrianus), assert that the Holy Spirit is often referred to as the Father and sometimes as the Son. And while we believe clearly in the Trinity, removing the third person, they do not want to be his substance, but his name. But in order not to take too long (for this is not a dialogue, but a commentary), I will briefly show the three spirits named in the fiftieth psalm, as the prophet says: Create a clean heart in me, O God, and renew a right spirit within me. Do not cast me away from your presence, and do not take your Holy Spirit from me. Give me the joy of your salvation, and strengthen me with your principal spirit. He calls the principal spirit Father, because the Son is from the Father, and not the Father from the Son. But the spirit of righteousness, truth, and justice signifies Christ the Lord: for the Father has given all judgment to the Son (John V, 22), as David says: O God, give your judgment to the king, and your power to the son of the king (Psalm LXXI, 1). Moreover, he calls the Holy Spirit by its explicit name. These things, although they differ in terms and persons, are associated by substance and nature: and the same Spirit, due to the fellowship of nature, is now called the Father, now the Son. However, the argument by which he endeavors to assert that we are no longer under the Law, but under the grace of the Lord Jesus, concludes with such a purpose. He had said above that we should receive the adoption of sons: now he proves that we are children of God by the Spirit whom we have in us. For never, he says, would we dare to say: Our Father who art in heaven: Hallowed be thy name, unless from the consciousness of the Spirit dwelling within us, and with a great voice of senses and teachings crying out: Abba, Father (Rom. VIII, 15). Abba is a Hebrew word, signifying the same as Father. And Scripture preserves this custom in several places, putting the Hebrew word in its own interpretation. Aser, riches. Tabitha, Dorcas (Acts IX): and in Genesis, Mesech, a slave (Gen. XV), and so on and so forth. However, since Abba Father is said in both Hebrew and Syriac language, and our Lord in the Gospel commands that only God should be called Father (Matt. XXIII), I do not know by what license we either call others by this name in monasteries, or consent to be called by it. And certainly, he himself commanded this when he said there should be no swearing (Matt. V). If we do not swear, we should not even mention anyone's father. If we interpret the father differently, we will be forced to have different opinions about swearing. It should also be noted that in the Scriptures, a shout is not understood as a loud voice, but as an expression of knowledge and the magnitude of teachings. For in Exodus, the Lord responded to Moses: Why do you cry out to me (Exodus 14:15)? when Moses' voice did not go before him. However, Scripture called it a shout when his heart was deeply moved and he groaned for the people with tears. Therefore, just as one who has the Spirit of the Son of God is a son of God, so in reverse, one who does not have the Spirit of the Son of God cannot be called a son of God. — Commentary on Galatians John Chrysostom : Had not we been first made sons, we could not have called Him Father. If then grace hath made us freemen instead of slaves, men instead of children, heirs and sons instead of aliens, is it not utter absurdity and stupidity to desert this grace, and to turn away backwards? — Homily on Galatians 4 Oecumenius : "For you are sons." And from where, he says, have we been deemed worthy of adoption as sons? From where? From the adoption by the Spirit who descended to prepare us and to teach (for this the One Crying indicates): to call God Father; which would not have been, if we had not been deemed worthy of adoption. And therefore have courage, O man, that you are no longer a slave, but a son of God and his heir. Because of the Son by nature having been incarnate and having taken on our whole humanity, you are no longer a slave and under the yoke of the law. How then is it not absurd for those who have become sons of God, through Christ and through the Spirit, to turn back again to the law? And behold the emphasis of the holy Trinity. The Father sent, the Son became incarnate, and the Spirit cooperated, who also having come into our hearts, teaches to say, Abba, Father. "also an heir through God by Christ Jesus." Through his cross. — Commentary on Galatians Tertullian : That we may have, therefore the assurance that we are the children of God, "He hath sent forth His Spirit into our hearts, crying, Abba, Father." For "in the last days," saith He," I will pour out of my Spirit upon all flesh. — Against Marcion Book V