When did God begin dealing with the nation of Israel as a distinct people?
The distinct nation of Israel began with the call of Abraham in Genesis 12. God pulled them out of the river of humanity and gave them covenant promises, law, priesthood, and civil law, dealing almost exclusively with them, though He made some exceptions and also dealt with Gentiles.
Les explains that the timeline of God's dealing with Israel begins with Genesis 12 and the call of Abraham. At that point God pulled the nation of Israel out of the river of humanity and promised them all the covenant promises given to the nation. He gave them the law, the priesthood, and the civil law—a nation that had the very mind of God expressed in their national behavior and in their understanding of the Spirit. God then sent the Messiah, intending that Israel would take the knowledge of Jehovah to the pagan Gentiles. But before that could happen, they rejected everything and crucified their Messiah. Les also notes that while God dealt almost exclusively with Israel, there were some exceptions where He dealt with Gentiles.