Romans 9:6–8
6 hBut it is not as though the word of God has failed. For inot all who are descended from Israel belong to Israel, 7 and not all are children of Abraham because they are his offspring, but j“Through Isaac shall your offspring be named.” 8 This means that it is not the children of the flesh who are the children of God, but the kchildren of the promise are lcounted as offspring.
Galatians 6:15
15 oFor neither circumcision counts for anything, nor uncircumcision, but a pnew creation.