Romans 9
This chapter is reasoning with the Jews, who were the chosen people, that now even the Gentiles are able to be part of God's Kingdom. As much as it does not seem fair, it is God's will. God is choosing, or allowing people in with his grace and not attainable through works. Maybe if we look at the Abraham's descendants, they were chosen not because of their works, but because of Abraham's righteousness. The only "works" were after the fact that they were chosen, and because they sinned against God, that sacrifices for the atonement of sin was necessary.
