Do not hastily misunderstand this statement. It does not mean that there was more sin after the Mosaic Law was given than before. It does mean that the knowledge and awareness of sin was increased by the giving of the Law.

If sin flowed free, grace overflowed. Grace flooded out sin. Grace outabounded sin. Sin in all its abundance is no match for the grace of God.

Sin abounded and grace superabounded (20). Sin reigned, but grace took over the throne and reigned instead (21a).

In other words universal subjection to death proves that sin has reigned universally. Death is unavoidable; it rules the race and mankind is not able to avoid its clutches or the sin that keeps it in dominion.

Those who put their faith in Him find themselves delivered from the dominion of sin and under the control of God’s gracious dealings. Paul will say more about this in the next chapter.

Most of all, the assurance of eternal life, as opposed to eternal death, is clear evidence that grace has reigned. The results of justification by faith in Christ’s blood are indeed superior to the results of Adam’s sin and humanity’s participation in that sin and its consequences.