Romans 9:7
Neither are all [Jewish] people children [of God], [simply] because they are Abraham's descendants. But [Gen. 21:12 says], "It is through Isaac that you [i.e., Abraham] will have descendants."
Hebrews 11:18
[even though] he had been told [by God, Gen. 21:12], "Your descendants will be traced through Isaac."
Luke 3:8
Demonstrate by your lives that you have [really] repented, and quit saying to yourselves, 'We claim Abraham as our forefather,' because I tell you, God is able to make Abraham's children out of these stones.
Luke 16:24-25
And he shouted out, 'Forefather Abraham, take pity on me and send Lazarus [to me], so he can dip the tip of his finger in water [and touch] my tongue to cool it, because I am in agony in these flames.'
Luke 16:30
Then the rich man said, 'No, forefather Abraham, but if someone goes to them from the dead, [then] they will repent [i.e., change their hearts and lives].'
John 8:33
They replied to Him, "We are descendants of Abraham and have never been slaves to anyone. How can you say, 'You will be set free'?"
John 8:37-39
I know that you people are [all] descendants of Abraham; yet you are trying to kill me because you will not allow my message to affect you.
Galatians 4:23
Now the son [Ishmael], born to the slave woman, was born simply of their natural relationship; but the son [Isaac], born to the free woman, was born in fulfillment of a [divine] promise.
Philippians 3:3
For we [Christians] are the [true] circumcision [i.e., the real "Jews" in God's eyes. See Rom. 2:28-29]. We worship by means of God's Holy Spirit [i.e., are empowered and motivated by the Holy Spirit], and boast in [the person and work of] Christ Jesus, and [we] place no confidence in the flesh [i.e., in any outward ritual or status for salvation].