Why does God impute His righteousness to someone's account?
God imputes His righteousness to a person’s account as a result of faith, not works, so no one may boast. It rests on the finished work of Christ accomplished on their behalf and appropriated by faith. When God saves, He also makes them His workmanship—a new person, not left as an old wreck.
Les explains that salvation is not of works, lest any man should boast, the same principle he said concerning Abraham in Romans 4. As a result of faith and the finished work of Christ accomplished on our behalf, appropriated by our faith, God has imputed His righteousness to our account. But God does not leave the saved person like a wreck. We are His workmanship; He makes us a new person and gives us a whole new personality, so we are not the old person we used to be. Les notes that workmanship may have the same Greek connection as symphony, and he illustrates how various instruments meld together for a beautiful sound.