Romans 11
17 And if some of the branches were broken off, and you, being a wild olive tree, were grafted in among them, and with them became a partaker of the root and fatness of the olive tree, 18 do not boast against the branches. But if you do boast, remember that you do not support the root, but the root supports you. 19 You will say then, “Branches were broken off that I might be grafted in.” 20 Well said. Because of unbelief they were broken off, and you stand by faith. Do not be haughty, but fear. 21 For if God did not spare the natural branches, He may not spare you either. 22 Therefore consider the goodness and severity of God: on those who fell, severity; but toward you, goodness, if you continue in His goodness. Otherwise you also will be cut off. 23 And they also, if they do not continue in unbelief, will be grafted in, for God is able to graft them in again. 24 For if you were cut out of the olive tree which is wild by nature, and were grafted contrary to nature into a cultivated olive tree, how much more will these, who are natural branches, be grafted into their own olive tree?
(NKJV)
Emphasis mine.
i dont think this is "replacement theology" per se, but rather "fulfillment theology".
Israel has always been described as the people of God who are His children, who follow Him and obey Him. Now, do the Jews of today follow and obey God? no, they dont. they still curse and blaspheme Jesus today, the same as they did in the days Jesus walked the earth... so, Yahweh used another people to fulfill His promises: the Gentiles. the body of Christ, or the church, consists of those who follow and obey Jesus... this is the same as the Israel of the Old Testament, so it is Biblical to say that the real Israel of God consists of those who follow and obey Jesus... so what was not fulfilled through the Jews, was fulfilled through the Gentiles.
now, does this mean that the national and fleshly Jews are done away with? absolutely not. no one is done away with. these flesh Jews still can repent of their sin and turn to Jesus Christ, just like any other human being can do before Christ returns.
keep in mind Ephesians 2:14-16
14 For He Himself is our peace, who has made both one, and has broken down the middle wall of separation,
15 having abolished in His flesh the enmity, that is, the law of commandments contained in ordinances, so as to create in Himself one new man from the two, thus making peace,
16 and that He might reconcile them both to God in one body through the cross, thereby putting to death the enmity.
at one point, there was a wall of separation between Jew and Gentile... that wall was, i believe, the Law of Moses. with the death of Jesus on the cross, that Mosaic Law has been fulfill in Jesus, so that the separation is no longer there, creating both Jew and Gentile one in the same through Jesus Christ.
we find the same type of language in Galatians 3:28-29
28 There is neither Jew nor Greek, there is neither slave nor free, there is neither male nor female; for you are all one in Christ Jesus.
29 And if you are Christ’s, then you are Abraham’s seed, and heirs according to the promise.
we must also remember Romans 11:18
do not boast against the branches. But if you do boast, remember that you do not support the root, but the root supports you.
in contrast with Romans 11:21-23
21 For if God did not spare the natural branches, He may not spare you either.
22 Therefore consider the goodness and severity of God: on those who fell, severity; but toward you, goodness, if you continue in His goodness. Otherwise you also will be cut off.
23 And they also, if they do not continue in unbelief, will be grafted in, for God is able to graft them in again.
we see in v.18 that the focus is not upon the branches themselves, but on the root. the root is what supports all branches, whether it they be natural, or wild.
we also see in v.21-23 that those who are considered Israel are those who continue in His goodness... the whole reason these fleshly Jews were taken out was because of their continual disobedience. God calls on those who was to be His children to live a life of holiness and righteousness, seeking the Lord in all they do... and as we read in v23, hope is not lost for the Jews. If they repent of their disobedience, and accept Christ as their Savior and Lord, God will graft them in again.
Jesus is indeed a righteous and just God, but He is also loving, merciful, and forgiving. upon true repentance, we will be reconciled unto the Lord through Jesus Christ.