God did not reject His people, whom He foreknew. Do you not know what the Scripture says about Elijah, how he appealed to God against Israel:
KJV
God hath not cast away his people which he foreknew. Wot ye not what the scripture saith of Elias? how he maketh intercession to God against Israel, saying,
ASV
God did not cast off his people which he foreknew. Or know ye not what the scripture saith of Elijah? how he pleadeth with God against Israel: