Paul here looks into the future. He asks whether God is finished with Israel forever. No, they are going to be blessed in the end! Look at your chart “E”. After the Lord takes the church (we believers) to heaven, then He is going to turn back to deal with Israel.
V.1-5 Remember that Elijah thought he was the only one in his days who was faithful to God. And the Lord had to tell him that 7,000 others had not bowed down to idol worship. God always has His faithful ones or remnant.
V.6 Grace is the opposite of works.
V.11-35 Through the rejection of the Messiah, God turned from the Jews, and has now offered His salvation to the whole world. (On chart “the day of grace”). When the Lord Jesus comes for us, then God is going to start to work on some of the Jews again, and He is going to open their blind eyes.
V.12-16 Israel rejected the Savior, through this rejection much good has come to the Gentiles. What a grand and glorious day it will be when Israel returns to God!
V.17-33 Israel was the natural branch of a tree. Because of unbelief they have been cut out, and other branches (the Gentiles) have been grafted in. But here the new branches are warned that if they do not continue on, they will be cut out, and then it will be easy to graft in again the natural branches. And that is exactly what is going to happen. After we believers are taken to heaven, the Jews shall be brought back into blessing in the millennium.
V.33 Paul bursts into praise to God for working out such a glorious plan.