Thus both we and you, all believers, became sons. That you truly are sons needs no distant proof. The testimony is in you yourselves: the Spirit dwelling in you. By Him your whole inner being is disposed to cry out to God: “Abba, Father!”
You could not have this Spirit if you were not sons. He is in you because you are sons, just as you are sons because He is in you. He made you sons, regenerating you by His grace and placing you in the rank of those born of God, who are His sons.
Having regenerated you, He dwells in you and keeps you in the feelings of sonship toward God. The Apostle’s expression suggests that, because you are sons, God sent the Spirit. In reality, the Holy Spirit makes believers in the Lord sons through regeneration.
Yet these moments need not be distinguished, for they enter into one another. Does the Spirit of God make all sons by regenerating them? Not all, but only those who have believed in the Lord, resolved to follow Him in everything, and for these dispositions have been received into God’s favor, as though foreordained to be sons.
After this, the Holy Spirit, coming through the mysteries, makes them sons substantially. Having made them such, He dwells in them and teaches them to rise up to God as Father.
In the course of the ordering of our salvation it was so: the time came to bring Jews and Gentiles spiritually into sonship. The Son of God came, accomplished everything preordained in the counsel of God concerning our salvation, and, having ascended into heaven, sent down the Holy Spirit from the Father.
Then this Spirit made sons of all who believed. The holy Apostle’s thought was to impress this: now everything extraneous must be cast aside. You see that the awaited time has come for men to be sons. You can see this clearly from the Spirit acting within you.
The Spirit is present. Seek nothing more. Lean on nothing else. Bind yourself by nothing. The Spirit cries in the hearts: “Abba, Father!”
This seems to be something mystical and hidden, acting in believers beyond consciousness, or deeper than consciousness. No, it truly exists and is consciously known by true believers who have within themselves the action of the Spirit of grace.
In such people the whole inner being is so attuned that they deeply feel themselves to be sons of God and know God as Father to them. This is the possession of all Christians.
Even now, those who have preserved the grace of baptism by living continuously as Christians should, feel themselves to be such. Those who have lost the grace of baptism cannot feel themselves to be such.
They must recover this grace through repentance. Then they must allow grace to gain mastery over them through the labors of self-denial, ascetic struggle, and good works. Then the same feeling of sonship toward God will be reborn in them.
So teach all the Spirit-bearing Fathers. To see that this is so, take for comparison the feelings of a slave who has gravely offended his master and expected nothing from him but death.
Yet, returning to him with repentance, he is mercifully received, caressed, and restored to his former rank. Such a servant cannot refrain from crying out from the depths of his soul to his master: “My own father!”
He will remain with this feeling thereafter. So it is in our spirit in relation to God. This is so essential in Christianity that whoever lacks such feeling toward God has not yet become a true Christian.
He either lives in negligence or has not yet reached the point at which the Holy Spirit becomes active in the heart. Since this subject is of first importance for us, I shall cite the words of all the ancient commentators who gave it their attention.
Blessed Jerome writes: “That we are sons, the Apostle proves from the Spirit Whom we have within ourselves. We would never have dared to cry, ‘Our Father, Who art in heaven,’ unless we were conscious within ourselves of the indwelling Spirit Who cries, ‘Abba, Father!’
Therefore, just as the one who has the Spirit of the Son of God is a son to God, so the one who does not have the Spirit of the Son of God cannot be called a son to God.”
Ambrosiaster reasons thus: “When he called the Gentiles who believed in Christ sons, though they were formerly enemies, there is no doubt that he also gives this name to the believing Jews, who, as is known, received this title long ago.
Yet they received this name only as an image, so that afterward it might be confirmed for them substantially through Christ. Without the Spirit it was not full and substantial.
So that we might have proof that we have truly been adopted by God, He gave us His Spirit. The Spirit shows the Father’s mark upon the sons. He gives us boldness to say to God what before, through weakness and unworthiness, we did not dare to say: ‘Abba, Father.’”
Blessed Augustine says this: “The Apostle said that we Jews were redeemed from under the law, that we might receive adoption. It remained to show that the same adoption belongs also to the Gentiles, who were not under the law.
He does this by mentioning the gift of the Holy Spirit given to all. Therefore Peter also defends himself before the believing Jews for having baptized Cornelius the uncircumcised centurion. He says that he could not forbid water to those who had already plainly received the Holy Spirit (cf. Acts 10:47).
Saint Paul had already used this most important proof above when he said: ‘Did you receive the Spirit by works of the law, or by the hearing of faith?’ (Gal 3:2).
So here too he says: ‘Because you are sons, God has sent the Spirit of His Son into your hearts, crying: Abba, Father!’”
Oecumenius speaks for all the Eastern Fathers, since all say the same: “How is it evident that we have been counted worthy of adoption? From the Spirit of adoption. He overshadowed us and teaches us, for this is what ‘crying’ means, to call God Father. This certainly would not be so if we had not been counted worthy of adoption.”