'Basis' in the Bible

since there is only one God who will justify the circumcised on the basis of faith and the uncircumcised by that same faith.

Why not? Because they did not pursue it on the basis of faith, but as if it were based on achievements. They stumbled over the stone that causes people to stumble.

But if this is by grace, then it is no longer on the basis of actions. Otherwise, grace would no longer be grace.