For you see sin, taking opportunity through the commandment, deceived me, and through it killed me. SIN is singular so we are still talking about the Sin Nature. The commandment clearly indicated that coveting was sin and Paul could clearly see that the sin of coveting was not external but came from the inside, from the sin nature. It is the deception that caused Paul to think he could live under the law, fulfill the law, and again experience life unto God through law-obedience. The result is often more guilt, more loss, more sense of defeat, more sense of dread and death.
All mankind go through a state of innocents based on ignorance.
This gives way to a state of guilt based on cognizance. The Law makes man cognizant of sins and the sin nature 4. Without the 10th commandment it was easy for Paul, a self-righteous Jewish leader, to see sins on the outside. Coveting or Lusting is something no one else sees, no one hears it, but it is there, very real, very much sin. That sin was an evidence of the presence of the OSN 7.