And if you be Christ's, then are you the seed of Abraham, heirs according to the promise.

but if ye are of Christ, then ye are Abraham's seed, heirs according to promise.

and if ye are of Christ then of Abraham ye are seed, and according to promise, heirs.

And if you belong to Christ, then you are indeed true descendants of Abraham, and are heirs in fulfilment of the promise.

And if you are Christ's, then you are Abraham's seed, and yours is the heritage by the right of God's undertaking given to Abraham.

If you are Christ's, then you are Abraham's offspring and heirs according to promise.

And if you are Christ's, then are you the offspring of Abraham, heirs according to the promise.

And, since you belong to Christ, it follows that you are Abraham's offspring and, under the promise, sharers in the inheritance.

Si autem vos Christi, ergo semen Abrahae estis, et secundum promissionem haeredes.

Then are ye Abraham's seed. This is not intended to convey the idea, that to be a child of Abraham is better than to be a member of Christ, -- but to repress the pride of the Jews, who gloried in their privilege, as if they alone were the people of God. They reckoned no distinction higher than to belong to the race of Abraham; and this very distinction he makes to be common to all who believe in Christ. The conclusion rests on this argument, that Christ is the blessed seed, in whom, as we have said, all the children of Abraham are united. He proves this by the universal offer of the inheritance to them all, from which it follows, that the promise includes them among the children. It deserves notice, that, wherever faith is mentioned, it is always his relation to the promise.

And if ye be Christ's - If you belong to the Messiah, and are interested in his work.
Then are ye Abraham's seed - The promise made to Abraham related to the Messiah. It was a promise that in him all should be blessed. Abraham believed in that Messiah, and was distinguished for his faith in him who was to come. If they believed in Christ, therefore, they showed that they were the spiritual descendants of Abraham. No matter whether they were Jews or Gentiles; whether they had been circumcised or not, they had the same spirit which he evinced, and were interested in the promises made to him.
And heirs according to the promise - See Romans 8:17. Are heirs of God. You inherit the blessings promised to Abraham, and partake of the felicity to which he looked forward. You have become truly heirs of God, and this is in accordance with the promise made to Abraham. It is not by the obedience of the Law; it is by faith - in the same way that Abraham possessed the blessing; an arrangement before the giving of the Law, and therefore one that may include all, whether Jews or Gentiles. All are on a level; and all are alike the children of God, and in the same manner, and on the same terms that Abraham was.

And if ye be Christ's - Or, as several good MSS. read, If ye be one in Christ. If ye have all received justification through his blood, and the mind that was in him, then are ye Abraham's seed; ye are that real, spiritual posterity of Abraham, that other seed, to whom the promises were made; and then heirs, according to that promise, being fitted for the rest that remains for the people of God, that heavenly inheritance which was typified by the earthly Canaan, even to the Jews.
1. The Galatians, it appears, had begun well, and for a time run well, but they permitted Satan to hinder, and they stopped short of the prize. Let us beware of those teachers who would draw us away from trusting in Christ crucified. By listening to such the Galatians lost their religion.
2. The temptation that leads us astray may be as sudden as it is successful. We may lose in one moment the fruit of a whole life! How frequently is this the case, and how few lay it to heart! A man may fall by the means of his understanding, as well as by means of his passions.
3. How strange is it that there should be found any backslider! that one who once felt the power of Christ should ever turn aside! But it is still stranger that any one who has felt it, and given in his life and conversation full proof that he has felt it, should not only let it slip, but at last deny that he ever had it, and even ridicule a work of grace in the heart! Such instances have appeared among men.
4. The Jewish covenant, the sign of which was circumcision, is annulled, though the people with whom it was made are still preserved, and they preserve the rite or sign. Why then should the covenant be annulled? This question admits a twofold answer.
1. This covenant was designed to last only for a time, and when that time came, having waxed old, it vanished away.
2. It was long before that void, through want of the performance of the conditions.
The covenant did not state merely, ye shall be circumcised, and observe all the rites and ceremonies of the law; but, ye shall love the Lord your God with all your heart, soul, mind, and strength, and your neighbor as yourself. This condition, which was the very soul of the covenant, was universally broken by that people. Need they wonder, therefore, that God has cast then off? Jesus alone can restore them, and him they continue to reject. To us the new covenant says the same things: Ye shall love the Lord, etc.; if we do not so, we also shall be cut off. Take heed, lest he who did not spare the natural branches, spare not thee; therefore, make a profitable use of the goodness and severity of God.

For if ye be Christ's,.... Or seeing ye are his, not by creation only, but by the Father's gift to him, by the purchase of his own blood, by the power of his grace, making them willing to give up themselves to him; not only his by profession, saying they are the Lord's, calling themselves by his name; but by possession, Christ dwelling in their hearts by faith, and they having his Spirit as a spirit of regeneration and adoption:
then are ye Abraham's seed; not his natural but his spiritual seed, the seed that should come, and to whom the promises were made, Galatians 3:16 and so were upon an equal foot even with the Jews that believed:
and heirs according to the promise; being the children of God, they are heirs of God; and being the spiritual children of Abraham, the children of the promise, which are counted for the seed, they are, according to the promise made to Abraham and his spiritual seed, heirs of the blessings of the grace of life, and of the eternal inheritance; of the blessing of justification of life, and of everlasting salvation; of this world and of the world to come; of all the spiritual blessings of the covenant of grace, and of the incorruptible and undefiled inheritance of the saints in light; to which they are begotten through the abundant mercy of God, for which they are made meet by the grace of Christ; and to which they have a right by his justifying righteousness.

and heirs--The oldest manuscripts omit "and." Christ is "Abraham's seed" (Galatians 3:16): ye are "one in Christ" (Galatians 3:28), and one with Christ, as having "put on Christ" (Galatians 3:27); therefore YE are "Abraham's seed," which is tantamount to saying (whence the "and" is omitted), ye are "heirs according to the promise" (not "by the law," Galatians 3:18); for it was to Abraham's seed that the inheritance was promised (Galatians 3:16). Thus he arrives at the same truth which he set out with (Galatians 3:7). But one new "seed" of a righteous succession could be found. One single faultless grain of human nature was found by God Himself, the source of a new and imperishable seed: "the seed" (Psalm 22:30) who receive from Him a new nature and name (Genesis 3:15; Isaiah 53:10-11; John 12:24). In Him the lineal descent from David becomes extinct. He died without posterity. But He lives and shall reign on David's throne. No one has a legal claim to sit upon it but Himself, He being the only living direct representative (Ezekiel 21:27). His spiritual seed derive their birth from the travail of His soul, being born again of His word, which is the incorruptible seed (John 1:12; Romans 9:8; 1-Peter 1:23).

If ye are Christ's - That is, believers in him.