A New Hope
By this point in time, the world had become much as we know it today. Many separate nations of people existed, with different languages, beliefs and customs. They all worshipped various different gods, in various different ways, and almost no one knew the One God or His Torah. If things continued in this manner, the knowledge of God and His Torah would be lost forever, and humanity would have no hope of ever returning and fulfilling its purpose.
However, it was not God's will that this be allowed to happen. He was working on a plan to preserve His Torah, so that when all of humanity finally decided to return to Him, they would be able to do so.
Forty-eight years before the building of the tower, a man named Avraham ("Abraham") was born. The Rambam tells us:
After this mighty man (Avraham) was weaned, he began to explore and think. Though he was a child, he began to think [incessantly] throughout the day and night, wondering: How is it possible for the sphere to continue to revolve without having anyone controlling it? Who is causing it to revolve? Surely, it does not cause itself to revolve.
He had no teacher, nor was there anyone to inform him. Rather, he was mired in Ur Kasdim among the foolish idolaters. His father, mother, and all the people [around him] were idol worshippers, and he would worship with them. [However,] his heart was exploring and [gaining] understanding.
Ultimately, he appreciated the way of truth and understood the path of righteousness through his accurate comprehension. He realized that there was one God who controlled the sphere, that He created everything, and that there is no other God among all the other entities. He knew that the entire world was making a mistake. What caused them to err was their service of the stars and images, which made them lose awareness of the truth.
Avraham was forty years old when he became aware of his Creator. When he recognized and knew Him, he began to formulate replies to the inhabitants of Ur Kasdim and debate with them, telling them that they were not following a proper path.
He broke their idols and began to teach the people that it is fitting to serve only the God of the world. To Him [alone] it is fitting to bow down, sacrifice, and offer libations, so that the people of future [generations] would recognize Him. [Conversely,] it is fitting to destroy and break all the images, lest all the people err concerning them, like those people who thought that there are no other gods beside these [images].
(Mishneh Torah, Hilkhoth Avodath Kokhavim 1:3)
From this point on, Avraham dedicated his life to teaching others about God and His Torah. Everywhere he went he strove with the residents of that place, and helped them return to the original teachings of their ancestors. Avraham taught these principles to his children, and his children taught them to their children.
In the merit of this exceptionally great man, God made a nation of people from his descendants. This nation would be devoted to protecting and spreading knowledge of God and His Torah to all of humanity. This is the nation of Israel – the Jewish people.
At Mount Sinai, God reiterated His Torah for Israel and all of humanity.
God decreed that the nation of Israel remain separate from the other nations of the world, so that they not fall back into the same errors that humanity had previously fallen into. Israel was also given many additional requirements, which would assist them in protecting the true teachings of the Torah and knowledge of God.
Their mission, to this day, is to be "a light to the nations," and to protect and safeguard the Torah. This is what is meant by the oft misunderstood statement that the Jews are the "chosen people."They were "chosen" to fulfill this mission.