Main point summary
Israel's rejection of Christ as a nation does not proof that the word of God is ineffective. It rather means that the blessings were true to the children of promise among the nation of Israel according to God's election so that no one can boast of their own achievements.
But it is not
that the word of God has taken no effect.
For they are not all Israel
who are of Israel,
nor are they all children
because they are the seed of Abraham;
but, “In Isaac your seed shall be called.”
That is, those who are the children of the flesh,
these are not the children of God;
but the children of the promise are counted as the seed.
For this is the word of promise:
“At this time I will come
and Sarah shall have a son.”
And not only this,
but when Rebecca also had conceived
by one man,
even by our father Isaac
(for the children not yet being born,
nor having done any good or evil,
that the purpose of God according to election might stand,
not of works
but of Him who calls),
it was said to her,
“The older shall serve the younger.”
As it is written,
“Jacob I have loved,
but Esau I have hated.”
Who are the true Israelits and who are the children of God
How one is a child of God
The ground of how one is a child of God. I.e. by election of God and not of works but His call.
Romans 9:6 If the blessings in verse 4 are Israels, but Israel rejected Christ, does that not mean that the word of God has taken no effect? Paul explains now that the word of God is effective based on the following understanding: Verse 6 - To be born into the nation of Israel does not mean to be of the same spirit as Jacob, who was called Israel after his encounter with the angle of the Lord. Verse 7-8 - Abraham received the promise of being the father of many. Abraham had many children but the promise became true through Isaac. So, there were only some that were the promised children, among the many decedents Abraham was father of . Verse 9-13 - These verses explain how someone is a child of God. God makes a promise which becomes true. Sarah was naturally unable to bear children, but God promised a child and Sarah gave birth to Isaac. The same is true for Rebecca. She was also unable to bear children till she got the promise of having twins. Furthermore, she got details foretold that the older would serve the younger, which all became true. The bases for the promises is the purpose of God according to His election. God calls and elects so that what is done, is not of the efforts of people but according to His purpose. People cannot boast therefore of anything in themselves because it is God's doing. People in themselves cannot do anything valuable to God because they are bankrupt, empty, and without power. They are just like Sarah and Rebecca who were naturally unable to give birth to a heir. Children of God are born supernaturally through accepting God's promise of eternal life in Jesus Christ. This is because of God's purpose to save mankind through His call and election.
For he is not a Jew
who is one outwardly,
nor is circumcision that
which is outward
in the flesh;