Why does Les call the singular word "sin" in Romans the "old Adam"?
The singular word "sin" in Romans is called "old Adam" because it refers to the Adamic sinful nature, the fountainhead of all our problems, not to individual acts. Plural "sins" are the fruit or things old Adam causes us to do.
Les explains that throughout Romans he uses "old Adam" in place of the singular word "sin" because that is what Paul is really talking about. He reminds listeners that when Paul speaks of sin in the singular, it is that old Adam, the fountainhead of all our problems, the Adamic sinful nature. The fruit of old Adam are the things we do, which are sins plural. So sin singular usually refers to old Adam, while sins plural are the things old Adam causes us to do. In the verse about what the law could not do, God sent His own Son in the likeness of sinful flesh and for sin to take the place of that old Adam, so that we could be crucified with Him and old Adam condemned in the flesh.
For what the law could not do, in that it was weak through the flesh, God sending his own Son in the likeness of sinful flesh, and for sin, condemned sin in the flesh:
More Questions
What does Paul mean by 'sin' in the singular in the book of Romans?
Throughout the book of Romans, when Paul speaks of 'sin' in the singular he is referring to old Adam, the Adamic sinful nature.
What are plural 'sins' in relation to the old Adam?
The plural word 'sins' refers to the fruit of the old Adam—the things that old Adam causes us to do.