Galatians 3:7, 8, 14, 29
Understand, then, that those who have faith are the sons of Abraham. . . .

Galatians 4:28
Now you, brothers, like Isaac, are children of the promise.

Romans 4:11, 16, 24
And he received the sign of circumcision as a seal of the righteousness that he had by faith while he was still uncircumcised. So then, he is the father of all who believe but are not circumcised, in order that righteousness might be credited to them. . . .