Just as the Scripture states. Spiritual Circumcision is the removal of the Sinful Nature, also known as the Mind of Satan compared to the Mind of Christ. The Sinful State of a "man" is Sarx in Greek. If you look at your footnotes, you will find the word "flesh" is in reference to Sarx, the sinful state of a person. Therefore, we must come to understand the difference in usage each time the word "flesh" is used. Sometimes it is used to described human flesh, but others, the Sinful Nature.
Galatians 3:13 from the NLT is the best translation for this passage. It states:
Galatians 3:13 NLT - "But Christ has rescued us from the curse pronounced by the law. When he was hung on the cross, he took upon himself the curse for our wrongdoing. For it is written in the Scriptures, "Cursed is everyone who is hung on a tree."
Other translations state that the Law of Moses is the Curse, but that's wrong, for the Law is Good, Righteous and Holy.
Romans 7:12 NLT - "But still, the law itself is holy, and its commands are holy and right and good."
So, the Purpose of Christ is to come to earth and redeem us of this Curse. That is the basis of John 3:16. The Work of Christ is to actually perform this Holy Operation of Faith. Now, here is the THIRD (interesting number, right?) element of Christ, and it is the Effect of Christ. And the effect of Christ is the Romans 12:2 Holy Transformation. Or, we could say that the Effect of Christ is for a person to be able to Love as described in 1 Cor chapter 13, the "Love Chapter." No one can Love in THAT way unless they have been Transformed by the Work of Christ, His Spiritual Circumcision.
So, when, in Romans 7, Paul stated that he was doing the things he didn't want to do . . . he was referencing his pre-transformed life. Look at what he said . . .
Romans 7:18-19 NLT - "And I know that nothing good lives in me, that is, in my sinful nature. I want to do what is right, but I can't. 19 I want to do what is good, but I don't. I don't want to do what is wrong, but I do it anyway."
Compare this, quickly, with Colossians 2:11 and 13 where he also said . . .
Colossians 2:11, 13 NLT - "When you came to Christ, you were "circumcised," but not by a physical procedure. Christ performed a spiritual circumcision--the cutting away of your sinful nature." ... 13 "You were dead because of your sins and because your sinful nature was not yet cut away. Then God made you alive with Christ, for he forgave all our sins."
In Romans 7, Paul is talking about his former life BEFORE the Sin Nature was removed. How could he write about possessing a Sinful Nature and then later talk about how the Work of Christ, which makes a person whole and complete, is cut out and permanently removed?
So, after a person has begun their Transformed, Romans 12:2 life, they will begin to say, "You know, the horrible things that I used to do, I no longer want to do them. Why? Because within the New Divine Nature of Christ, I hate sin. I have been Enabled to not only hate my sin, but I am learning to stop it altogether. So, the things I once did, I no longer do them."
2 Peter 1:4 NLT - "And because of his glory and excellence, he has given us great and precious promises. These are the promises that enable you to share his divine nature and escape the world's corruption caused by human desires."
These are the Promises that are spoken of to Abraham and Sarah in Genesis chapters 17!
The removal of the Sinful Nature is done so, so as to be replaced by the Divine Nature. Now get this . . . what is the job of the Human Nature? It SERVES! So whatever Nature we possess, we will serve "it." And this is why the Mind of Satan must be replaced by the Mind of Christ.
You are about to be totally Transformed, FrancisClare!