Masha,
Read thoroughly the account of Moses receiving Torah at Sinai.
You will discover in your reading that Ha'Shem declares that the Jews are the only people who would receive The Law, due to their character traits of being so "stiff-necked" and "stubborn" that they would keep it and refuse to give it up. Also, you will read how Moses actually argued face to face with Ha'Shem and won the argument! Ha'Shem was so angered with the rebellious Children of Israel that he was going to destroy them all...Moses successfully argued that they be spared, convincing Ha'Shem that if he were to destroy them, the rest of the world would all say that the miracles of the Exodus from Egypt, and the Jewish People's receiving Torah, were merely lies and myth, and they would claim that the "disappearance" of the Jews would be proof positive that their G-d was not the One True G-d!