Romans 11:23-25

23And if they do not persist in unbelief, they will be grafted in, for God is able to graft them in again. 24For if you were cut from a wild olive tree, and contrary to nature were grafted into one that is cultivated, 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 will not be conceited: A hardening in part has come to Israel, until the full number of the Gentiles has come in.