4 ^1-7 But you must realise that so long as an heir is a child, though he is destined to be master of everything, he is, in practice, no different from a servant. He has to obey a guardian or trustee until the time which his father has chosen for him to receive his inheritance. So is it with us: while we were “children” we lived under the authority of basic moral principles. But when the proper time came God sent his son, born of a human mother and born under the jurisdiction of the Law, that he might redeem those who were under the authority of the Law and lead us into becoming, by adoption, true sons of God. It is because you really are his sons that God has sent the Spirit of his Son into your hearts to cry “Father, dear Father”. You, my brother, are not a servant any longer; you are a son. And, if you are a son, then you are certainly an heir of God through Christ.

Consider your own progress: do you want to go backwards

^8-11 At one time when you had no knowledge of God, you were under the authority of gods who had no real existence. But now that you have come to know God, or rather are known by him, how can you revert to dead and sterile principles and consent to be under their power all over again? Your religion is beginning to be a matter of observing certain days or months or seasons or years. Frankly, you stagger me, you make me wonder if all my efforts over you have been wasted!

I appeal to you by our past friendship, don’t be misled

^12-16 I do beg you to follow me here, my brothers. I am a man like yourselves, and I have nothing against you personally. You know how handicapped I was by illness when I first preached the Gospel to you. You didn’t shrink from me or let yourselves be revolted at the disease which was such a trial to me. No, you welcomed me as though I were an angel of God, or even as though I were Jesus Christ himself! What has happened to that fine spirit of yours? I guarantee that in those days you would, if you could, have plucked out your eyes and given them to me. Have I now become your enemy because I continue to tell you the same truth?

^17-20 Oh, I know how keen these men are to win you over, but can’t you see that it is for their own ends? They would like to see you and me separated altogether, and have you all to themselves. Don’t think I’m jealous—it is a grand thing that men should be keen to win you, whether I’m there or not, provided it is for the truth. Oh, my dear children, I feel the pangs of childbirth all over again till Christ be formed within you, and how I long to be with you now! Perhaps I could then alter my tone to suit your mood. As it is, I honestly don’t know how to deal with you.

Let us see what the Law itself has to say

²¹ Now tell me, you who want to be under the Law, have you heard what the Law says?

^22-27 It is written that Abraham had two sons, one by the slave and the other by the free woman. The child of the slave was born in the ordinary course of nature, but the child of the free woman was born in accordance with God’s promise. This can be regarded as an allegory. Here are the two agreements represented by the two women: the one from Mount Sinai bearing children into slavery, typified by Hagar (Mount Sinai being in Arabia, the land of the descendants of Ishmael, Hagar’s son), and corresponding to present-day Jerusalem—for the Jews are still, spiritually speaking, “slaves”. But the free woman typifies the heavenly Jerusalem, which is the mother of us all, and is spiritually “free”. It is written: ‘Rejoice, O barren, you who do not bear! Break forth and shout, you who do not travail! For the desolate has many more children than she who has a husband.’

^28-30 Now we, my brothers, are like Isaac, for we are children born “by promise”. But just as in those far-off days the natural son persecuted the “spiritual” son, so it is today. Yet what is the scriptural instruction? ‘Cast out the bondwoman and her son, for the son of the bondwoman shall not be heir with the son of the freewoman.’

³¹ So then, my brothers, we are not to look upon ourselves as the sons of the slave woman but of the free, not sons of slavery under the Law but sons of freedom under grace.