Galatians 3:26

For ye are all the children of God
Not by nature, as Christ is the Son of God, for he is the only begotten of the Father, and in such sense as neither angels nor men are the sons of God; nor by creation, as Adam and all mankind, and the angels are; but by divine adoption by an act of God's rich and sovereign grace, putting them among the children in saying this the apostle directs himself to the Gentiles for their comfort, and says this of them all in a judgment of charity, they being under a profession of faith; lest they should think, because they were not Abraham's seed according to the flesh, nor were ever trained up under the law as a schoolmaster, that they were not the children of God: whereas they were such not by the law, as none indeed are,

but by faith in Christ Jesus;
not that faith makes any the children of God, or puts them into such a relation; no, that is God's own act and deed; of his free rich grace and goodness, God the Father has predestinated his chosen ones to the adoption of children, and has secured and laid up this blessing for them in the covenant of grace; Christ by redemption has made way for their reception and enjoyment of it; the Spirit of God, in consequence of their sonship, as a spirit of adoption bears strong reason and argument, proving that they are not under the law as a schoolmaster, in which light it is here set by the apostle; since they are sons and not servants, and so free from the bondage of the law; they are sons grown up into the faith of Christ, and are led and taught by the Spirit of God, as they are that are the children of God by faith; and as is promised to the saints under the Gospel, that they shall be "all taught of God"; and therefore stood in no need of the law as a schoolmaster, which only was concerned with the Jews, whilst they were children under age; and has nothing to do with such, whether Jews or Gentiles, who believe in Christ, and are growing up into him their head, till they come to the measure of the stature of the fulness of him.