"...they were asking Him, saying, “Lord, is it at this time You are restoring the kingdom to Israel?” He said to them, “It is not for you to know times or epochs which the Father has fixed by His own authority..." Acts 1"6-7 NASBWas the church intended by God as a replacement to Israel? There is no doubt that the new covenant in Christ displaced the old covenant of Moses. That was a covenant of works entered into primarily by the children of Jacob, whereas the new is a covenant of faith entered into by whoever will. If the point of the old was to make way for the new, than a justifiable question arises as to the continuing need or viability of a covenantal people whose identifying covenant is obsolete. What would be the point of a covenant-people if their covenant is defunct?
The church, most definitely, is the new kingdom of God. It is the one and only locus of right relationship with God in this and in the ages to come. In regard to covenantal relationship with God it displaces Israel, encompassing Jew and Gentile in one body as the people of God. Those selected for inclusion in this kingdom are chosen, not on the basis of geneology and faith, but on the basis of faith alone. It is the only game in town.
But even if the old is defunct and discarded as to it's ability to establish and regulate covenantal relationship with God, God's promise to Abraham concerning the land given to his offspring and God being their God still remains in force. The Mosaic covenant cannot regulate their fellowship with God (only the Messiah's can do that), yet the Abrahamic covenant is still in force and controls their geopolitical destiny here on earth.
Acts 1:7 is proof. Jesus was asked specifically about Israel's earthly destiny--his answer was not that they did not have one any more. He answered that the timing of the restoration of Israel's earthly kingdom was information God was keeping to himself. In other words, there was coming a restoration of earthly kingdom to Israel in the future, but the time and date was unknown to all but God. Ultimately, that kingdom will be governed in its covenantal relationship with God by the covenant of Messiah not Moses, but there is most certainly still purpose in God for the continued existence of national Israel, despite their present unbelief.
After his resurrection and just prior to his ascension, in Jesus' mind there was still a kingdom to restore to Abraham's descendants in the promised land. In his mind there was still a place and purpose for national Israel. That they would have to relate to God in the same way as Gentiles in order to be right with God (faith in Christ) does nothing to mitigate the fact of God's continuing purpose for their existence. In his plans at that time there was still a place for the kingdom of the Jews.
That tells me that there still is.