Gal 4:1-3. “But I say, that so long as the heir is a child, he differeth nothing from a bond-servant, though he is lord of all; but is under guardians and stewards, until the term appointed of the father. So we also when we were children, were held in bondage under the rudiments of the world.”
The word “child” in this place denotes not age but understanding; meaning that God had from the beginning designed for us these gifts, but, as we yet continued childish, He let us be under the elements of the world, that is, new moons and sabbaths, for these days are regulated by the course of sun and moon. If then also now they bring you under law they do nothing else but lead you backward now in the time of your perfect age and maturity. And see what is the consequence of observing days; the Lord, the Master of the house, the Sovereign Ruler, is thereby reduced to the rank of aservant.
Gal 4:4-5. “But when the fulness of the time came God sent forth His Son, born of a woman, under the Law that he might redeem them which were under the Law, that we might receive the adoption of sons.”
Here he states two objects and effects of the Incarnation, deliverance from evil and supply of good, things which none could compass but Christ. They are these; deliverance from the curse of the Law, and promotion to sonship. Fitly does he say, that we might “receive,” “[be paid,]” implying that it was due; for the promise was of old time made for these objects to Abraham, as the Apostle has himself shown at great length. And how does it appear that we have become sons? he has told us one mode, in that we have put on Christ who is the Son; and now he mentions another, in that we have received the Spirit of adoption.
Gal 4:6-7. “And because ye are sons, God sent forth the Spirit of His Son into your hearts, crying, Abba, Father. So that thou art no longer a bond-servant, but a son; and if a son, then an heir through God.”
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?