Which, if the Nation Israel HAD accepted Christ as their Messiah at His first coming, would have happened. But we know that they, as a Nation, rejected Him. But we also know that He will return to set up His Kingdom. "THE DAYS ARE COMING"..
RIght now, they are blinded and set aside, but after the Body of Christ is raptured, God will once again deal with Israel as a nation. "THE DAYS ARE COMING"..THAT is when He will be their God and they will be His people. A nation of priests and a blessing to all nations.
The Church the Body of Christ replaces NOTHING in God's Plan. We are NOT a replacement for Israel. We are NOT spiritual Israel. Israel is Israel. We (the Body of Christ) are a mystery, hid in God, from before the foundation of the world. There is neither Jew nor Gentile during this time. A believer is a believer and is placed in the Body of Christ, in this age of the grace of God.
Jeremiah is prophecy, dealing with prophetic things concerning the Nation Israel. We are God's mystery, not made known until revealed to Paul. A sort of parenthesis in God's ongoing Plan. Acts, chapters 8,9,10 are the perfect example.
I hope that answers your question!