I too have been charged with believing replacement theology which is a degrogoratry term in their thinking.
I simply turn to Romans 11 which shows that we have been grafted into spiritual isreal.
17If some of the branches have been broken off, and you, though a wild olive shoot, have been grafted in among the others and now share in the nourishing sap from the olive root, 18do not boast over those branches. If you do, consider this: You do not support the root, but the root supports you. 19You will say then, “Branches were broken off so that I could be grafted in.” 20Granted. But they were broken off because of unbelief, and you stand by faith. Do not be arrogant, but be afraid. 21For if God did not spare the natural branches, he will not spare you either.
22Consider therefore the kindness and sternness of God: sternness to those who fell, but kindness to you, provided that you continue in his kindness. Otherwise, you also will be cut off. 23And if they do not persist in unbelief, they will be grafted in, for God is able to graft them in again. 24After all, if you were cut out of an olive tree that is wild by nature, and contrary to nature were grafted into a cultivated olive tree, how much more readily will these, the natural branches, be grafted into their own olive tree!
25I do not want you to be ignorant of this mystery, brothers, so that you may not be conceited: Israel has experienced a hardening in part until the full number of the Gentiles has come in. 26And so all Israel will be saved, as it is written:
“The deliverer will come from Zion;
he will turn godlessness away from Jacob.
27And this is[f] my covenant with them
when I take away their sins.”[g]
28As far as the gospel is concerned, they are enemies on your account; but as far as election is concerned, they are loved on account of the patriarchs, 29for God’s gifts and his call are irrevocable. 30Just as you who were at one time disobedient to God have now received mercy as a result of their disobedience, 31so they too have now become disobedient in order that they too may now[h] receive mercy as a result of God’s mercy to you. 32For God has bound all men over to disobedience so that he may have mercy on them all.