How does God impute His righteousness to a person's account?
God imputes His righteousness to a person's account as a result of faith, based on the finished work of Christ accomplished on their behalf. The believer receives it through faith, not by works, so no one can boast. It is not earned by human effort.
Les explains that verse 9 says 'not of works, lest any man should boast,' which is the same thing that was said concerning Abraham in Romans 4. Verse 10 shows that as a result of our faith, and because of the finished work of Christ accomplished on our behalf—now appropriated by our faith—God has imputed His righteousness to our account. But God expects something: we are His workmanship. When God saves us, He does not leave us like a wreck; He makes us a new person, gives us a whole new personality, so we are not the old person we used to be. The word workmanship, Les suggests, has the same Greek connection as 'symphony,' where various instruments meld together for a beautiful sound.