The first thing that Paul notes is the unfailing nature of of God’s promises.
Romans 9:6 ESV
But it is not as though the word of God has failed. For not all who are descended from Israel belong to Israel,
Numbers 23:19 ESV
God is not man, that he should lie, or a son of man, that he should change his mind. Has he said, and will he not do it? Or has he spoken, and will he not fulfill it?
God's Plan is His Own (v. 6)
Romans 9:6 ESV
But it is not as though the word of God has failed. For not all who are descended from Israel belong to Israel,
Isaiah 14:24 ESV
The Lord of hosts has sworn: “As I have planned, so shall it be, and as I have purposed, so shall it stand,
God's Purposes are Sure (v. 7)
Romans 9:7 ESV
and not all are children of Abraham because they are his offspring, but “Through Isaac shall your offspring be named.”
Isaiah 46:10 ESV
declaring the end from the beginning and from ancient times things not yet done, saying, ‘My counsel shall stand, and I will accomplish all my purpose,’
God's Power is Complete (v. 8-9)
Romans 9:8–9 ESV
This means that it is not the children of the flesh who are the children of God, but the children of the promise are counted as offspring. For this is what the promise said: “About this time next year I will return, and Sarah shall have a son.”
