Nor is "born under law" a distinction intended to limit the previous term, as though it meant a born Jew, and not a mere woman's son. This expression, to the mind of the reader of ch. iii., conveys the idea of subjection, of humiliation rather than eminence. "Though He was (God's) Son," Christ must needs "learn His obedience" (Heb. v. 8). The Jewish people experienced above all others the power of the law to chasten and humble. Their law was to them more sensibly, what the moral law is in varying degree to the world everywhere, an instrument of condemnation. God's Son was now put under its power. As a man He was "under law;" as a Jew He came under its most stringent application. He declined none of the burdens of His birth. He submitted not only to the general moral demands of the Divine law for men, but to all the duties and proprieties incident to His position as a man, even to those ritual ordinances which His coming was to abolish. He set a perfect example of loyalty. "Thus it becometh us," He said, "to fulfil all righteousness."
The Son of God who was to end the legal bondage, was sent into it Himself. He wore the legal yoke that He might break it. He took "the form of a servant," to win our enfranchisement. "God sent forth His Son, human, law-bound—that He might redeem those under law."
Redemption was Christ's errand. We have learned already how "He redeemed us from the curse of the law," by the sacrifice of the cross (ch. iii. 13). This was the primary object of His mission: to ransom men from the guilt of past sin. Now we discern its further purpose—the positive and constructive side of the Divine counsel. Justification is the preface to adoption. The man "under law" is not only cursed by his failure to keep it; he lives in a servile state, debarred from filial rights. Christ "bought us out" of this condition. While the expiation rendered in His death clears off the entail of human guilt, His incarnate life and spiritual union with believing men sustain that action, making the redemption complete and permanent. As enemies, "we were reconciled to God by the death of His Son;" now "reconciled, we shall be saved by His life" (Rom. v. 10). Salvation is not through the death of Christ alone. The Babe of Bethlehem, the crowned Lord of glory is our Redeemer, as well as the Man of Calvary. The cross is indeed the centre of His redemption; but it has a vast circumference. All that Christ is, all that He has done and is doing as the Incarnate Son, the God-man, helps to make men sons of God. The purpose of His mission is therefore stated a second time and made complete in the words of ver. 5 b: "that we might receive the adoption of sons." The sonship carries everything else with it—"if children, then heirs" (ver. 7). There is no room for any supplementary office of Jewish ritual. That is left behind with our babyhood.
2. So much for the ground of sonship. Its proof lay in the sending forth of the Spirit of the Son.
The mission of the Son and that of the Spirit are spoken of in vv. 3-6 in parallel terms: "God sent forth His Son—sent forth the Spirit of His Son," the former into the world of men, the latter "into" their individual "hearts." The second act matches the first, and crowns it. Pentecost is the sequel of the Incarnation (John ii. 21; 1 Cor. vi. 19, 20). And Pentecost is repeated in the heart of every child of God. The Apostle addresses himself to his readers' experience ("because ye are sons") as in ch. iii. 3-6, and on the same point. They had "received the Spirit:" this marked them indubitably as heirs of Abraham (ch. iii. 14)—and what is more, sons of God. Had not the mystic cry, Abba, Father, sounded in their hearts? The filial consciousness was born within them, supernaturally inspired. When they believed in Christ, when they saw in Him the Son of God, their Redeemer, they were stirred with a new, ecstatic impulse; a Divine glow of love and joy kindled in their breasts; a voice not their own spoke to their spirit—their soul leaped forth upon their lips, crying to God, "Father, Father!" They were children of God, and knew it. "The Spirit Himself bore them witness" (Rom. viii. 15).
This sentiment was not due to their own reflection, not the mere opening of a buried spring of feeling in their nature. God sent it into their hearts. The outward miracles which attended the first bestowment of this gift, showed from what source it came (ch. iii. 5). Nor did Christ personally impart the assurance. He had gone, that the Paraclete might come. Here was another Witness, sent by a second mission from the Father (John xvi. 7). His advent is signalised in clear distinction from that of the Son. He comes in the joint name of Father and of Son. Jesus called Him "the Spirit of the Father;"[114] the Apostle, "the Spirit of God's Son."
To us He is "the Spirit of adoption," replacing the former "spirit of bondage unto fear." For by His indwelling we are "joined to the Lord" and made "one spirit" with Him, so that Christ lives in us (ch. ii. 20). And since Christ is above all things the Son, His Spirit is a spirit of sonship; those who receive Him are sons of God. Our sonship is through the Holy Spirit derived from His. Till Christ's redemption was effected, such adoption was in the nature of things impossible. This filial cry of Gentile hearts attested the entrance of a Divine life into the world. The Spirit of God's Son had become the new spirit of mankind.
Abba, the Syrian vocative for father, was a word familiar to the lips of Jesus. The instance of its use recorded in Mark xiv. 36, was but one of many such. No one had hitherto approached God as He did. His utterance of this word, expressing the attitude of His life of prayer and breathing the whole spirit of His religion, profoundly affected His disciples. So that the Abba of Jesus became a watchword of His Church, being the proper name of the God and Father of our Lord Jesus Christ. Gentile believers pronounced it, conscious that in doing so they were joined in spirit to the Lord who said, "My Father, and your Father!" Greek-speaking Christians supplemented it by their own equivalent, as we by the English Father. This precious vocable is carried down the ages and round the whole world in the mother-tongue of Jesus, a memorial of the hour when through Him men learned to call God Father.
"Because ye are sons, God sent forth the Spirit," with this cry. The witness of sonship follows on the adoption, and seals it. The child is born, then cries; the cry is the evidence of life. But this is not the first office of the Holy Spirit to the regenerate soul. Many a silent impulse has He given, frequent and long continued may have been His visitations, before His presence reveals itself audibly. From the first the new life of grace is implanted by His influence. "That which is born of the Spirit, is spirit." "He dwelleth with you, and is in you,"[115] said Jesus to His disciples, before the Pentecostal effusion. Important and decisive as the witness of the Holy Spirit to our sonship is, we must not limit His operation to this event. Deeply has He wrought already on the soul in which His work reaches this issue; and when it is reached, He has still much to bestow, much to accomplish in us. All truth, all holiness, all comfort are His; and into these He leads the children of God. Living by the Spirit, in Him we proceed to walk (ch. v. 25).
The interchange of person in the subject of vv. 5-8 is very noticeable. This agitated style betrays high-strung emotion. Writing first, in ver. 3, in the language of Jewish experience, in ver. 6 Paul turns upon his readers and claims them for witnesses to the same adoption which Jewish believers in Christ (ver. 5) had received. Instantly he falls back into the first person; it is his own joyous consciousness that breaks forth in the filial cry of ver. 6b. In the more calm concluding sentence the second person is resumed; and now in the individualising singular, as though he would lay hold of his readers one by one, and bid them look each into his own heart to find the proof of sonship, as he writes: "So that thou art no longer a slave, but a son; and if a son, also an heir through God."