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.