The Jews (from name Judah) were chosen to be a holy people through a special covenant God made with them when Moses was their leader.
Deuteronomy 7:6-8 For thou art an holy people unto the LORD thy God: the LORD thy God hath chosen thee to be a special people unto himself, above all people that are upon the face of the earth. The LORD did not set his love upon you, nor choose you, because ye were more in number than any people; for ye were the fewest of all people: But because the LORD loved you, and because he would keep the oath which he had sworn unto your fathers
God wanted them to be an example to all other nations of the world; they were to be God’s witnesses on earth.
Exodus 19:6 And ye shall be unto me a kingdom of priests, and an holy nation.
Isaiah 43:10 Ye are my witnesses, saith the LORD, and my servant whom I have chosen: that ye may know and believe me, and understand that I am he: before me there was no God formed, neither shall there be after me.
They largely failed to keep God’s covenant.
They were promised blessings if they kept God’s laws and curses if they disobeyed him.
Deuteronomy 28:1 & 2 And it shall come to pass, if thou shalt hearken diligently unto the voice of the LORD thy God, to observe and to do all his commandments which I command thee this day, that the LORD thy God will set thee on high above all nations of the earth: And all these blessings shall come on thee, and overtake thee, …….(a long list follows).
Deuteronomy 28:15 But it shall come to pass, if thou wilt not hearken unto the voice of the LORD thy God, to observe to do all his commandments and his statutes which I command thee this day; that all these curses shall come upon thee, and overtake thee….. (a very long list follows).
The curses include - Deuteronomy 28:37 And thou shalt become an astonishment, a proverb, and a byword, among all nations whither the LORD shall lead thee. (This shows the truth of the Bible because this has clearly happened).
Deuteronomy 28:64 & 65 And the LORD shall scatter thee among all people, from the one end of the earth even unto the other; and there thou shalt serve other gods, which neither thou nor thy fathers have known, even wood and stone. And among these nations shalt thou find no ease, neither shall the sole of thy foot have rest: but the LORD shall give thee there a trembling heart, and failing of eyes, and sorrow of mind: (This again has been fulfilled. The Jews have been scattered into all nations and yet retain their identity and witness to the truth of the God’s word. Anti-semitism is referred to here).