John Calvin Commentary Isaiah 45:25

"In Jehovah shall all the seed of Israel be justified, and shall glory." — Isaiah 45:25 (ASV)

In Jehovah shall be justified. He now makes a brief reply to an objection which might be urged: it appeared absurd to say that the Lord called the Gentiles, who had always been alienated from Him. “Is it in vain that the Lord has chosen the seed of Abraham? Is His promise void, which He so frequently repeated?” (Genesis 15:5 and Genesis 17:7).

In order to remove this doubt, he declares that the Lord will nevertheless stand by His promises. Though He chooses the Gentiles, the covenant He made with the fathers will not fall to the ground, because the elect people will enjoy the privileges of their rank.

Nor does he in this passage, as in many others, speak of the rejection of that nation; but the Prophet simply shows that the grace of God, which will be diffused throughout the whole world, will flow from that fountain.

As for the greater number having been rejected by God, this still did not set aside God’s covenant, because the remnant of adoption were always the true and lawful Israel. Although they were few in number, they were nevertheless the first-born in the Church. Besides, all those among the Gentiles who had been grafted into that body also began, as we have formerly seen, to be accounted children of Abraham.

“One shall say, I belong to Jacob; another shall subscribe with his hand, I am a descendant of Israel.” (Isaiah 44:5).

And on this ground we are now reckoned the genuine Israel of God, though we are not the descendants of Israel. The Prophet therefore added this, both so that the Jews might not think that the Lord’s covenant had failed, and so that they might not boast of their birth and despise the Gentiles.

All the seed of Israel. He extends this seed further, so that they may not suppose that it ought to be limited to the family of Abraham; for the Lord gathers His people without distinction from among Jews and Gentiles, and here he speaks universally of the whole human race.

Shall be justified and shall glory. It ought to be observed that the Prophet says that we “are justified and glory in the Lord,” for in no one else ought we to seek “righteousness” or “glory.” He has joined “glory” to it, which depends on “righteousness” and is added to it. Hence Paul also says:

“Where is thy glorying? It is excluded. By what law? Of works? No, but by the law of faith.” (Romans 3:27).

And again:

“If Abraham was justified by works, he hath glory, but not before God.” (Romans 4:2).

It follows, therefore, that they alone deservedly glory who seek their righteousness in God and acknowledge that in themselves they have no ground for glorying.