A Commentary by John Stott
Verse 4: *But when the time had fully come… *. Man’s bondage under the law continued for about 1,300 years. It was a long and arduous minority. But at last the fulness of time arrived (cf. Mk.1:15) – the date set by the Father when the children should attain their majority, be freed from their guardians and inherit the promise.
Why is the period of Christ’s coming termed ‘the fulness of the time’ (AV)? Various factors combined to make it such. For instance, it was the time when Rome had conquered and subdued the known inhabited earth, when Roman roads had been built to facilitate travel and Roman legions had been stationed to guard them. It was also the time when the Greek language and culture had given a certain cohesion to society. At the same time, the old mythological gods of Greece and Rome were loosing their hold on the common people, so that the hearts and minds of men everywhere were hungry for a religion that was real and satisfying. Further, it was the time when the law of Moses had done its work of preparing men for Christ, holding them under its tutelage and in its prison, so that they longed ardently for the freedom with which Christ could make them free.
When this fulness of time had come, God did two things.
*First, God sent his Son.* Verse 4,5: *When the time had fully come, God sent forth his Son, born of woman, born under the law, to redeem those who were under the law, so that we might receive adoption as sons*. Notice that God’s purpose was both to ‘redeem’ and to ‘adopt’; not just to rescue from slavery, but to make slaves into sons. (‘The metaphor comes from the Graeco-Roman [but not Jewish] legal device whereby a wealthy childless man might take into his family a slave youth who thus, by a great stroke of fortune, ceased to be slave and become a son and heir’ [Hunter, p.33]). We are not told here how the redemption was achieved, but we know from Galatians 1:4 that it was by the death of Christ and from 3:13 that this death was a ‘curse-bearing’ death. What is emphasized in these verses is that the one whom God sent to accomplish our redemption was perfectly qualified to do so. He was God’s Son. He was also born of a human mother, so that He was human as well as divine, the one and only God-man. And He was born ‘under the law’, that is, of a Jewish mother, into the Jewish nation, subject to the Jewish law. Throughout His life He submitted to all the requirements of the law. He succeeded where all others before and since have failed: He perfectly fulfilled the righteousness of the law. So the divinity of Christ, the humanity of Christ and the righteousness of Christ uniquely qualified Him to be man’s redeemer. If He had not been man, He could not have redeemed men. If He had not been a righteous man, He could not have redeemed unrighteous men. And if He had not been God’s Son, He could not have redeemed men for God or made them the sons of God.
*Secondly, God sent His Spirit*. Verse 6: *And because you are sons, God has sent the Spirit of His Son into our hearts, crying, ‘Abba! Father!’*. The Greek verbs translated ‘sent forth’ (verse 4) and ‘has sent’ (verse 6) are the same word and in the same tense (*exapesteilen*). There was, therefore, a double sending forth from God the Father. Observe the Trinitarian reference. First, God sent His Son into the world; secondly, He sent His Spirit into our hearts. And entering our hearts, the Spirit immediately began to cry ‘Abba! Father!’, or, as the parallel passage in Romans 8:15, 16 puts it: ‘When we cry “Abba! Father!” it is the Spirit himself bearing witness with our spirit that we are children of God.’ ‘Abba’ is an Aramaic diminutive for ‘Father’. It is the word that Jesus Himself used in intimate prayer to God. J.B.Phillips renders it: ‘Father, dear Father.’ Thus God’s purpose was not only to secure our sonship by His Son, but to assure us of it by His Spirit. He sent His Son that we might have the *status* of sonship, and He sent His Spirit that we might have an *experience* of it. This comes through the affectionate, confidential intimacy of our access to God in prayer, in which we find ourselves assuming the attitude and using the language not of slaves, but of sons.
So the indwelling presence of the Holy Spirit, witnessing to our sonship and prompting our prayers, is the precious privilege of all God’s children. It is ‘because you are sons’ (verse 6) that God has sent the Spirit of His Son into our hearts. No other qualification is needed. There is no need to recite some formula, or strive after some experience, or fulfil some extra condition. Paul says to us clearly that *if* we are God’s children, and *because* we are God’s children, God has sent His Spirit into our hearts. And the way He assures us of our sonship is not by some spectacular gift or sign, but by the quiet inward witness of the Spirit as we pray.
Verse 7: *So*, Paul concludes this stage of his argument,…*you are no longer a slave but a son, and if a son then an heir*. And this changed status is *through God*. What we are as Christians, as sons and heirs of God, is not through our own merit, nor through our own effort, but ‘through God’, through His initiative of grace, who first sent His Son to die for us and then sent His Spirit to live in us.