The apostle shows that, as an heir in nonage is under tutors and guardians, so were the Galatians while under the law; and, as the heir when he comes of age is no longer under guardians, so they, when the Gospel came, arrived at full maturity, and were redeemed from the law, Gal 4:1-3. He shows, farther, that when the fullness of the time came God sent forth his Son, that we might obtain the adoption of sons, and have the strongest evidence of that adoption, Gal 4:4-6. Those who are children of God are heirs of heaven, Gal 4:7. He compares their former and latter state, and shows the reason he had to fear that his labor on their behalf was in vain, Gal 4:8-11. He mentions his trials among them, and their kindness to him, Gal 4:12-16. Shows his tender affection for them, and exhorts them to return to the Gospel, Gal 4:17-20. Shows the excellence of the Gospel beyond that of the law, by the allegory of Mount Sinai and Jerusalem, Gal 4:21-27. Shows also that the believing Gentiles are children of the promise, as Isaac was; and have been elected in the place of the Jews, who have been cast out according to the Scriptures, Gal 4:28-31.
Verse 1
The heir, as long as He is a child - Though he be appointed by his father's will heir of all his possessions yet till he arrive at the legal age he is master of nothing, and does not differ from one of the common domestics.