for in Christ Jesus you are all sons of God, through faith.
26. For ye are all the children of God. It would be unjust, and in the highest degree unreasonable, that the law should hold believers in perpetual slavery. This is proved by the additional argument, that they are the children of God. It would not be enough to say that we are no longer children, unless it were added that we are freemen; for in slaves age makes no alteration.
The apostle having just before been speaking of the promise made to Abraham, and representing that as the rule of our justification, and not the law, lest they should think he did too much derogate from the law, and render it altogether useless, he thence takes occasion to discourse of the design and tendency of it, and to acquaint us for what purposes it was given.
Commenting on Galatians 3:19-29
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...