Romans 11:5-7, 23-24, 28-32

Even so then at this present time also there is a remnant according to the election of grace. But if it is by grace, it is no more of works: otherwise grace is no more grace. What then? That which Israel seeketh for, that he obtained not; but the election obtained it, and the rest were hardened

And they also, if they continue not in their unbelief, shall be grafted in: for God is able to graft them in again. For if thou wast cut out of that which is by nature a wild olive tree, and wast grafted contrary to nature into a good olive tree; how much more shall these, which are the natural branches, be grafted into their own olive tree?

As touching the gospel, they are enemies for your sake: but as touching the election, they are beloved for the fathers’ sake. For the gifts and the calling of God are not repented of. For as ye in time past were disobedient to God, but now have obtained mercy by their disobedience, even so have these also now been disobedient, that by the mercy shown to you they also may now obtain mercy. For God hath shut up all unto disobedience, that he might have mercy upon all.