Basically nobody actually teaches "Replacement Theology", what the historic and orthodox teaching of Christianity is, as what Scripture itself very explicitly teaches, is that Israel and the Church are the same People, the same body. Israel is the Church, the Church is Israel. God has always had a People who belong to Him through faith. That is why St. Paul is clear that Abraham is our father in the faith, not the father of the Jews only, but father of all the Faithful, Jew and Gentiles; as the promise given to Abraham is Jesus Christ who is the Seed of Abraham. And in Christ both Jew and Gentile are united as one body.
Those before Christ looked forward in faith to Christ. And we today have the fullness of Christ. The Word became flesh, being conceived in the womb of the Virgin Mary by the power of the Holy Spirit, He is Jesus the Christ, the One about whom all who came before longed for and hoped for: Emmanuel, the Son of David, the Root of Jesse, the Seed of Abraham, the Son of Man.
We can't go so far as to say that unbelieving Israel isn't Israel at all, they are still Israel in that, as Jews, they are heirs of the promises made to them through Moses on Mt. Horeb; just as during the time of Elijah many in Israel had become faithless, there remained a faithful remnant. Paul uses this imagery of the time of Elijah to speak of the present faithlessness of much of Israel, while also speaking of the faithful remnant who have believed in God's Messiah. St. Paul, recognizing this current situation looks forward, with hope, to a time when all of Israel, not just the faithful remnant, will be saved. How or what that looks like is not told to us, but it does mean that Christians do err if we consider the Jews somehow completely outside of God's designs and grace.
So there is an important and fine point that must be made: The Dispensationalist rejection of the Gospel by insisting that Christ's precious Gospel is only a temporary thing given, and that God's "real" plan is simply to carry on an earthly territory in the Levant which is entirely apart from Christ, His work, and the fullness of God in Him and all the holy promises given fulfilled in Him; this schema must be denied for what it is: a dangerous rejection of Christ and His Everlasting Gospel of salvation for all sinners for all times, the Gospel of the kingdom of God, inaugurated and manifest through Christ and His Church until all things are consummated in the end and Jesus hands the kingdom over to His Father and God is all in all. Likewise, we must not think that unbelieving Israel is completely and utterly cut off from God, as the Apostle himself says that though the unbelieving have been pruned away, he nevertheless (as mentioned already) looks forward in hope to the salvation of all Israel. As such, the Church must never be the antagonist against any people, but in a special way the historic antagonism, and indeed antisemitism, of the Christian Church is particularly heinous--both for its severity, and for its betrayal of hope.
-CryptoLutheran
