Malachi 3:6

But now the moment had come to unfold it. The Almighty One stood forth, pledged to Israel as the I AM — the self-existent and therefore unchanging One, always true and faithful to His word. Israel's history proved this again and again. At the end of the Old Testament God said, "I the LORD do not change; therefore you, O children of Jacob, are not consumed."

All God's dealings, whether in judgment or mercy, rest on the unchanging nature of God. That is why He formally declares His unchanging character before He calls them to repentance… God does not change in holiness, and therefore He must chasten His people when they sin. Neither does God change in His purposes of grace and blessing, and therefore His people are not consumed.

Verse 6 gives the guarantee of all this: the unchangeable character of the LORD. We might have expected the next words to be, "Therefore you sons of Jacob must be consumed." They are just the opposite. God exercises much patience, and He has power to reach His own purpose in the end. The Apostle Paul asks, "Has God rejected His people?" and he at once answers, "By no means!" (Rom. 11:1). When Christ comes again, judgment will fall on the Jew, yet God will preserve and bless a godly remnant of the sons of Jacob. The same thing is true today.

Take the golden calf, for example. They set it up in the camp, and by it they broke the covenant of Sinai and earned the penalty of death. On what ground did the LORD spare His guilty people? It was on the ground of His oath to Abraham, Isaac, and Jacob (Ex. 32:12-13). So it was in the sovereignty of His grace, and in His faithfulness to His word, that He was gracious to whom He would be gracious, and showed mercy to whom He would show mercy (Ex. 33:19). This is a sure foundation on which His people can rest in every age and in every dispensation.

That sight was the exact mark of Israel under the covenant of law: in complete failure, yet not destroyed. "For I the LORD do not change; therefore you, O children of Jacob, are not consumed" (Mal. 3:6). They presumed to obey the law given through Moses, and forgot God's promises to the fathers — promises the LORD never forgot. Despite their self-confidence, the bramble bush went on burning, but never burned up, because He, the Eternal, had promised.

He waited three thousand five hundred years before He would say these words. He waited until man, until Israel, until Judah, until the remnant brought back from Babylon — until all had corrupted their way. Then He tells out what He always is — the resource of faith — the unchanging God! If God could change, nothing would be secure: there would be nothing left to rest on.

Under the government of God the nation of Israel had passed through many a change, but His purpose for them remains unaltered. "The gifts and calling of God are irrevocable" (Rom. 11:29). These remain, God does not change His mind, and because the LORD does not change, the sons of Jacob were not consumed.