How did God lose His chosen people Israel in the story of Joseph and Egypt?
Israel was God's covenant people until, because of the brother's sin, Joseph ended up down in Egypt. While Joseph was in Egypt and the other brethren were in rebellion, God lost His chosen people and lost control of them. He therefore had to buy them back, which Exodus describes as redemption through the blood of the Passover lamb.
Les explains that the nation of Israel were God's covenant people until, because of the brother's sin, Joseph ended up down in Egypt. While Joseph was down in Egypt and the other brethren were in rebellion, God lost His chosen people; He had lost control of them. So what was He going to do? He would have to buy them back. That is what the book of Exodus is all about—it is a book of redemption. How did He buy them back? Through the blood of the Passover lamb. Les ties this to the larger scriptural theme that something owned was lost and needs to be redeemed. The same pattern applies today: even Gentiles in the Age of Grace rest on the blood of that lamb, having sinned and come short of God's glory but being justified freely by His grace through redemption in Christ Jesus.