Comes this blessedness then on the circumcision only, or on the uncircumcision also?…
The position is now established that righteousness is through faith. But, they might say, through the faith of a circumcised man; and the promise of the inheritance was through the Law; and surely the posterity of Abraham came according to the flesh. He answers - Righteousness, heritage, posterity, by faith alone.
1. The righteousness of faith without circumcision. In Gem 15. we have the record of Abraham's justification; the institution of circumcision is narrated in Genesis 17., fourteen years after. Abraham, therefore, was justified "in his Gentile-hood" (see Godet). Therefore, he is the father of Gentile believers; and in so far as he is the father of Jewish believers, it is because they are believers, not because they are Jews.
2. Circumcision a seal of the righteousness of faith. God strengthens man's faith by visible signs and seals of the faith and of its results. So to Abraham circumcision was an abiding pledge that God accepted his faith for righteousness. And likewise the existence of a separated nation was a testimony to the world. But it was the faith alone that was effectual; circumcision did but attest.
II. HERITAGE. The whole world is promised to the heirs of Abraham as a heritage; this of itself might suffice to show that the heirs are not merely descendants according to the flesh. But the condition of such inheritance shall show the meaning.
1. If the heritage were through Law, then faith and the promise fail.
(1) "Faith is made void;" for it cannot grasp an impossibility, nor can it rightly lay hold of that which must be worked for.
(2) "And the promise is made of none effect;" for an unfulfilled Law works God's wrath towards man, which is in utter contrariety to the fulfilment of a promise of love.
2. Therefore the heritage is of faith, that it may be according to grace, etc.
(1) Faith the sole condition of promise, that while God's grace gives freely, man may freely receive.
(2) Faith the sole characteristic of the heirs of the promise, that so the seed may be, not merely that which is of the Law (even combined with faith), but that which is of faith (apart from Law), comprising beth Jews and Gentiles who are the spiritual children of the great believer.
III. POSTERITY. But it might be objected that an Israel according to the flesh was necessary, in order that the spiritual Israel might be at last accomplished. Truly. But, to cut away the last ground of boasting, even the Israel according to the flesh was the gift of God through faith.
1. The obstacles to such faith. "His own body," etc. And this all full in view: "he considered."
2. The warrant of faith. While viewing the obstacles, he staggered not.
(1) God's promise "A father of many nations." "So shall thy seed be.
(2) God's power. "Able to perform;" "quickeneth the dead," etc. "Wherefore also it was reckoned unto him for righteousness." As before, it was virtually the faith of his spiritual salvation; yes, the very faith which laid hold of the promise of posterity - a posterity that they deemed according to the flesh. Let us learn that by faith we may be righteous, by faith we may possess the earth, By faith we may impress for good the generations following. What an heirship is possible through the faith of one believer! - T.F.L.
Parallel VersesKJV: Cometh this blessedness then upon the circumcision only, or upon the uncircumcision also? for we say that faith was reckoned to Abraham for righteousness.