Abraham & Justification By Faith, Not by works or following the law of circumcision

Romans 4:1 What then shall we say that Abraham our father has found according to the flesh?
2 For if Abraham was justified by works, he has something to boast about, but not before God.
3 For what does the Scripture say? "Abraham believed God, and it was accounted to him for righteousness."
4 Now to him who works, the wages are not counted as grace but as debt.
5 But to him who does not work but believes on Him who justifies the ungodly, his faith is accounted for righteousness,
6 just as David also describes the blessedness of the man to whom God imputes righteousness apart from works:
7 "Blessed are those whose lawless deeds are forgiven, And whose sins are covered;
8 Blessed is the man to whom the LORD shall not impute sin."
9 Does this blessedness then come upon the circumcised only, or upon the uncircumcised also? For we say that faith was accounted to Abraham for righteousness.
10 How then was it accounted? While he was circumcised, or uncircumcised? Not while circumcised, but while uncircumcised.
11 And he received the sign of circumcision, a seal of the righteousness of the faith which he had while still uncircumcised, that he might be the father of all those who believe, though they are uncircumcised, that righteousness might be imputed to them also,
12 and the father of circumcision to those who not only are of the circumcision, but who also walk in the steps of the faith which our father Abraham had while still uncircumcised.