This is one of those pulpit slogans that is repeated throughout the world, but in itself it is a very vague statement.
It does not tell us who God considers to be His Israel or what He still intends to do with it.
Our interpretation of the name should not matter, as it was God who gave it to Jacob.
Those who can put their politics aside while reading Gal 6:14-16 will see in the context that the "Israel of God" contains believers in Jesus from all nations.
While in that chapter, have a look at Gal 3:26-29. Notice that the same group of people are also called "Abraham's seed, and heirs according to the promise."
Rom 11:26 actually confirms that God uses the word "Israel" in reference to all who are in Christ, because the "all Israel" that is to be saved is illustrated in the previous verses as an olive tree, again containing believers in Jesus from all nations.
So why do those who love the theology of Judaism call us "replacement theologians"?
Surely all Christians know that Jesus is the living King of true Israel in line of David?
All His disciples were Israelite s, so no controversy there.
Does all this confusion arise from the fact that Cornelius and others like him were grafted in?
Why are they such game changers?
Should we have not already started calling the Hebrews "replacement theologians" when Ruth was grafted, or even Rahab?
If that is the case, replacement Theology must definitely began with Abraham.
He lived before Israel was named, yet received the promises of Genesis 12 and 15.
Before naming anyone "replacement theologian" we should also be sure we understand exactly who is included in Abraham's promise. Abraham and his "SEED" (kjv). 'Seed" is most definitely a reference to Christ, as you can see in Gal 3:16, and includes His believers from all nations.
In conclusion I wish to challenge you with the suggestion that those who wish to replace Christ in this context with the modern nation of Israel are in fact the true replacement theologians.
Have you ever actually studied any of this subject in detail? I'm accused of following a rabbit trail. As it happens, it's something like that. God has not put a special section in His word that relates to Israel in the end times. It's found in Daniel, Ezekiel, Amos, Zechariah, Jermiah and other places.
What people seem to ignore is that God's covenant with Abraham included the land. if you can find where God rescinded that covenant, which He Himself called everlasting, please let me know. According to my reading, the sun will not rise and the moon will not orbit the earth before God's covenant will end.
I don't know anyone who believes that Israel replaces Christ. That is stupid and heretical. Jews are saved exactly the same way as gentiles. However, Israel the nation is at the centre of God's plan and purpose for the world. Read Zechariah 14. Don't tell me it has been fulfilled. It has not.