God called Abraham to found a new nation (Neh. 9:17). People call him "the father of the Jews" (John 8:39).
God promised Abraham a posterity (Gen. 15:1-6). However, he got impatient and yielded to his wife's suggestion that he have a son by her Egyptian maid, Hagar (Gen. 16:1-6). This was a pagan custom and outside of the will of God.
God kept His promise. When Abraham was one hundred and Sarah ninety, God gave them a son, Isaac. He is called the "son of promise" (Gen. 17, 18, 21: Gal. 4:23, 28).
Isaac married Rebekah. They had twin sons, Esau and Jacob. God said, "The elder shall serve the younger"—Jacob (Gen. 25:19-26). Jacob's name means "supplanter." He took advantage of his brother's weakness and obtained the birthright (Gen. 25:27-34). Rebekah and Jacob schemed and Jacob obtained the blessing also (Gen. 27). Later, Jacob's name was changed to Israel, prince with God. This marked a change in his life as well (Gen. 32:24-32).
God loved Jacob. He did not always go after things in the right way, but he had a desire for spiritual things. Esau cared for the things of this world; he despised his birthright.
God chose His people, the Jews, that through them the gospel might spread throughout the world. "But they mocked the messengers of God, and despised His words, and misused His prophets, until the wrath of God arose against His people, till there was no remedy" (2 Chron. 36:16). Therefore He set them aside temporarily that the fullness of the Gentiles might come in.
The Gentiles also are called a "chosen generation...an holy nation" (I Pet. 2:9). (Gentile pertains to anyone who is not a Jew by birth.) This present age is called "the times of the Gentiles." The gospel has encircled the globe, as many have come to Christ. But many do not believe.
One day the Jews will inherit their homeland, and a remnant will come to Christ.
When God says Gentiles are “a chosen generation...an holy nation,” He refers to believing Gentiles. He calls us to live holy lives, not perfect, but above reproach. He also says, “Pray for the peace of Jerusalem: they shall prosper that love thee.” Do we pray for the Jews as we ought? Do we truly love them? Then God promises to prosper us. This does not necessarily mean worldly prosperity, but God will make us successful. In God’s eyes success means to lay up heavenly treasures, not earthly.