Not as if the word of God had fallen to the ground; for all are not Israel, who are of Israel. Neither because they are the seed of Abraham, are they all children, but in Isaac shall thy seed be called: That is, not the children of the flesh are the children of God, but the children of the promise are counted for the seed.

Romans 11:2-7

God hath not rejected his people whom he foreknew. Know ye not what the scripture saith of Elijah? how he pleadeth with God against Israel, Lord, they have killed thy prophets, and digged down thy altars; and I am left alone, and they seek my life. But what saith the answer of God to him? I have reserved to myself seven thousand men, who have not bowed the knee to Baal. read more.
And so likewise at the present time, there is a remnant, according to the election of grace. But if by grace, then it is no more of works: else grace is no longer grace. And if it be of works, then it is no more grace; else work is no longer work. What then? Israel hath not obtained that which he seeketh, but the election hath obtained, and the rest were blinded.