Replacement theology is something that continues to raise its head, but that’s not surprising considering its roots go very deep – right back to the early days of gentile inclusion within the church. As more gentiles were added, and especially after the late first century exile of Israel from the Land, the idea of replacement theology strengthened.
Here are some of the important points related to this issue:
1) God has NOT changed the identity of Israel or shifted that identity from one group of people to another
2) God’s promises and prophecies related to Israel remain and apply to blood descendants of Abraham, Isaac and Jacob
3) The gentile church has not become Israel – not a “spiritual Israel” or “the new Israel”
4) We should not confuse today’s political nation of Israel with the Israel of God. God’s Israel also exists beyond the borders of the land He promised to that people, and while many inhabit the promised land, most are still scattered among the nations.
5) One day God will bring ALL of His Israel back to the land He promised to them
6) One day all of Israel will recognise their Messiah and will be ruled by Him (both son of David and Son of God)
Here are links to a few articles dealing with these points that I’ve I posted earlier:
https://onesimusfiles.wordpress.com/2013/04/20/refined-not-redefined/
https://onesimusfiles.wordpress.com/2012/07/31/gospel-of-the-kingdom-what-about-israel/
https://onesimusfiles.wordpress.com/2012/08/01/one-new-man-and-the-gospel-of-a-jewish-messiah/
http://onefiles.blogspot.co.nz/2010/02/gods-future-for-israel.html
Onesimus Files 
One note for understanding [while I think you’ve stated things well]: Even if there were a word in the Bible for church, as if this word is an English translation for whatever that word was (and there are basically two different words from Greek that could be considered candidates but really aren’t when studied comparatively in context)… EVEN IF, nevertheless, people meeting to honor Jesus would not have been gentile (as in entirely or even primarily early on — until, as you suggested, later… especially after all Jews were thrown out of Israel [then renamed as a snub] by decree of Rome… and even more especially when the new Rome of Constantine (centuries later) declared that the church or his [Constantine’s/Papa’s] communion couldn’t possibly have Jewish character or room for anyone identified as a Jew (and Jew was to be a slur as he used it in that way). So, church, if we do take it as proper translation (which I don’t), would not be definitionally gentile. As an extension of that, there is not a gentile church and a Jewish church.
Replacement Theology also has pretty close ties with Germany and anti-Semitism. I think Luther did more to solidify the theological weird view of Israel than any other theologian. I do not see how a person can read the OT and not come away with knowing that God will restore Israel. You have to do some pretty fancy mental gymnastics to avoid that point.
Sadly “mental gymnastics” is the favoured sport of many professing christians. They try all kinds of twists and turns to avoid accepting what scripture clearly reveals.
There have been quite a few who contributed their part, but I agree Luther (sadly) was one of them. I read somewhere that he wasn’t theologically weird in his early reformation studies but became so over time. Still, he put forward a condition when he made his condescending statement(s) [about Jews]. He was making an assumption (something about Israel being reestablished as a nation I think) like a proverbial “when hell freezes over” — of course, not foreseeing what has now happened (as observed in the 20th century). So, he’s been proven wrong by his own reasoning in that regard. Yet, while I’m glad he’s been proven wrong, I tend to agree the current political situation is not God’s full promised restoration.
“Replacement theology” is typical of labels—these lead to confusion and division. I don’t believe Paul talks about Israel’s replacement but rather in Israel’s expansion–to include gentiles who believe. Yet I affirm with you, Onesimus, that God has not annulled his covenant with the Jews.
However, I cannot find any New Testament reference to an entity called “the gentile church”. The church is always simply “the church”. I find abundant evidence that true believers have, in Jesus, become part of the historic people of God, having been incorporated into Israel’s Messiah and grafted into the true rootstock of the olive tree. Paul tells us that we were “all baptized by (or into) one Spirit so as to form one body—whether Jews or Gentiles, slave or free—and we were all given the one Spirit to drink.” According to Paul in Romans 4 and Galatians 3, gentiles in Jesus are also heirs of the promise to Abraham, the promise that comes by faith, and he declares Abraham is the father of us all.
Elsewhere, you have posted that the promise in Ezekiel 36 is meant for literal Israel alone. But Paul uses similar phrases found in Ezekiel 36 in his joyous affirmations about being led by the Spirit. Do you then also say that the new covenant promised in Jeremiah 31 is also just for “the house of Israel and the house of Judah”?
Further examples could be given where a promise or prophecy made to Israel has been applied in the New Testament to all the people of God. There is James’ conclusion that by the prophet Amos, foretelling God’s rebuilding of David’s fallen tent, “the rest of mankind may seek the Lord, including the gentiles who bear His name.”
I think that when Paul says “all Israel will be saved” he has in mind all those Jews whom God will save in the future, and not just the many thousands of Jews already in the Body of Christ, with the believing gentiles.
Ian I used the term “gentile church” because it is gentiles who see themselves as “the church” who have replaced Israel. It is gentiles who consider that God has rejected Israel and turned His favour towards a gentilised church: a church that rejects everything considered “Jewish”, the kind of church that replaced Passover with Easter, Pentecost with Whitsuntide and in the past required Jewish “converts” to Christianity to eat pork to prove the legitimacy of their faith in Christ.
Ezekiel 36 and Jeremiah 31 are addressed to Israel and refer to Israel’s restoration to Him, and their return to the land He promised to them. As gentile believers we are grafted into Israel’s new covenant with God – though for gentile believers it’s not technically “new” – considering we were not part of “the old”.
I see that Paul’s statement “all Israel will be saved” refers to the future when all surviving Jews will recognise their messiah, enter the new covenant and be totally restored to the land.