The gentiles and unincorporated Paul writes to have not been under Jewish Law. Not being under the Law, one has to wonder if it is even possible to sin since the Law has not been received. Paul here testifies about the doctrine of imputation. There was a time before the Jewish religion. There was a time when the Law had not been given at all. Therefore, it is not the Law that can possibly make a person a sinner or righteous. Without the Law, God does not impute sin to anyone because He is just. If God has not given His Law, He does not expect people to know it. Yet, even before the Law, people suffered the consequence of sin in death—even those who did not sin in the likeness of Adam, directly disobeying a perspicuous command from God. How can this be?
Since Adam was the federal head, all people were made sinners when he sinned. This is a matter of our spiritual estate—not a matter of outward law-keeping. Though sin is not imputed to us, we are sinners by federal inheritance. This is true with or without the Law. The Law only came in to make that estate obvious—to increase the trespass. No one is condemned because he or she is unable to keep God’s Law. Throw that out of your mind. We are condemned because of the natural-born condition of our hearts. We are not sinners because we sin. We sin because we are sinners.
Since through one man’s disobedience many were made sinners, through another man’s (Jesus Christ’s) obedience many will be made righteous. Though the many, even apart from the Law, inherited Adam’s sinful heart, the many will be given Christ’s righteous heart as a gift.
One is neither condemned nor justified according to his own works—whether or not he kept the Law. We are condemned based on the condition of our hearts if we are not in Christ and still bear the estate of Adam. We are justified based on the condition of our hearts if we are in Christ and now bear His righteousness through His obedience.