"By sending his own Son in the likeness of sinful flesh and for sin, God condemned sin in the flesh." Romans 8:3
“Condemned sin in the flesh.”
Whose sin? Mine.
Whose flesh? His.
We live and die by this: Substitution.
"For all who are led by the Spirit of God are sons of God." Romans 8:14.
So here is a test to see if you are a Christian. Are you led by the Spirit of God?
Led in what sense?
The “for” creates a link with v. 13 which gives the answer, namely, “led” into war with your sin.