Replacement theology, in a nutshell, teaches that the ancient Israelites were the people of God in some way, shape, or form. However, due to their turning aside from God and rejecting Christ, God has now done away with ancient Israel, and is instead doing a new thing with a new people of God, a new Israel, namely, the Church. The Church, because of her faithfulness to God, has replaced apostate Israel in the plans of God. Ancient Israel and whatever God was doing through it, has now been replaced by the Church.
However, it must be questioned, is this Biblical? It is beyond the scope of this post to explore this issue in its fullness. However, in my reading of Scripture recently, I stumbled across a passage that I would like to present for your consideration, as an example of why I believe replacement theology to be wrong.
In Exodus 32, we read of how Moses was delayed in coming down from the mountain. The children of Israel grew impatient waiting on Moses to return. Their inability to wait on Moses' return is magnified by the sabbath day commandment given to Moses at the same time while on the top of the mountain in the closing verses of chapter 31. While Moses was receiving instruction on the sabbath rest in chapter 31, the children of Israel were growing restless in chapter 32.
Their restlessness finds its full manifestation in an idolatrous orgy that erupts at the bottom of the mountain. For such is in full keeping with man who has an innate inability to wait on God and rest. He must "do something." But when we would feel the itch to do something, God is attempting to show us we must wait and rest. For the itching to do something is the expression of man's constant desire and ability to do something in and of himself. Whereas the sabbath stands in stark contrast with mans nature, and is instead an invitation to be like God through rest.
To continue on with the chapter...
Israel takes its gold and gives it to Aaron to make a golden calf out of. The work of their hands is then attributed with the miraculous deliverance that God provided the nation from Egyptian bondage. Indeed, it is said of the golden calf, "This is your God who brought you up out of the land of Egypt!" Israel has "quickly" (32:8) turned away from God in apostasy. We then read:
Exodus 32:9 The Lord said to Moses, "I have seen this people, and behold, they are an obstinate people. 10 Now then let Me alone, that My anger may burn against them and that I may destroy them; and I will make of you a great nation."
Replacement theologians here would be tempted to give the Lord a great "Amen!" But not Moses. For Moses was no replacement theologian. Rather, in this outburst of anger Moses steps in and intercedes for the apostate nation:
Exodus 32:11 Then Moses entreated the Lord his God, and said, "O Lord, why does Your anger burn against Your people whom You have brought out from the land of Egypt with great power and with a mighty hand? 12 Why should the Egyptians speak, saying, 'With evil intent He brought them out to kill them in the mountains and to destroy them from the face of the earth'? Turn from Your burning anger and change Your mind about doing harm to Your people. 13 Remember Abraham, Isaac, and Israel, Your servants to whom You swore by Yourself and said to them, 'I will multiply your descendants as the stars of the heavens, and all this land of which I have spoken I will give to your descendants, and they shall inherit it forever.'"
So great was Moses intercession for his people that we read in the next verse, "So the Lord changed His mind about the harm which He said He would do to His people." (32:14) On what basis does God change His mind, and on what basis does God decide to continue with the nation and not start over with Moses?
In verse 12 Moses appeals to the fact that God did deliver the nation out of Egypt, and to destroy them would be to destroy the purposes for which He brought them out for. Such would be seen as God acting contrary to His purposes in the eyes of the nations, and to have done all that He did in vain. Then in verse 13 Moses appealed to the promises and covenant God established with the patriarchs: Abraham, Isaac, and Israel. It is interesting here we read "Israel" instead of the normal triune formula of "Jacob." For here Moses did not appeal to the righteousness of the people themselves for why they deserve to be spared, rather, here Moses appealed to the righteousness of the patriarchs as the basis for their receiving mercy. "Remember... Your servants," Moses says! Moses appeal for their continuation as a nation depended not on their actions or their righteousness, rather, it depended entirely on the righteousness of another.
Such, ultimately is a type of Christ and the righteousness we have in Him. As sinners, we deserved the wrath of God. We, like Israel, quickly turned aside from God. However, we are made right with God, not because of anything we have done to deserve God's mercy. Rather we were made right with God, "through the obedience of the One." (Romans 5:19) Thus, the righteousness of another, that is Christ, is imputed (charged) to our account and is the basis of our salvation. Therefore, when Moses appealed to the righteousness of the patriarchs and the promises God made to them as the basis of Israel's salvation from God's wrath, he was asking God to impute the righteousness of the patriarchs to the nation. Such is no different than the appeal Christ makes for us as our Advocate to the Father for our salvation from His wrath. For we are saved not because of anything we have done, but because of the righteousness of Another. For we are saved by grace.
Thus, to suggest as replacement theologians have done, that Israel has fallen and is done with and that God has a new people, is the same as to say that salvation is not by grace, but rather by works. "After all, those apostate Christ killers deserve to be cut off!" And indeed, they do deserve to be cut off as a nation because of their crucifying of Christ. But Christ, who God raised up as a prophet "like [Moses]" (Deuteronomy 18:15), stands before the Lord to appeal to Him that the nation not be destroyed, for Christ came and confirmed the promises made to the Fathers (Romans 15:8), and appeals to the Lord for the continuation of the nation as the people of God, not on the basis of what they have done or their righteousness, but rather, on the basis of a righteousness entirely foreign to them... just like Moses.