Romans 5:20

The law. Literally, “law” (see on chapters 2:12; 5:13). It is clear from verses 13, 14 that Paul is thinking of the time of Moses as the occasion when “law” entered. It was at Sinai that God’s laws for the guidance of His people were formally stated, though His moral law of ten commandments was written in Adam’s heart at creation.

Entered. Greek pareiserchomai, literally, “to come in beside.” The word occurs elsewhere in the New Testament only in Galatians 2:4, where it is translated “came in privily.”

Might abound. This was not the primary purpose of law, which was to reveal the standard of righteousness. But because of men’s inherited and cultivated tendency to evil, the effect of law was actually to multiply transgression. Law had this effect because it prohibited certain sinful acts which up to that time had not been recognized as sinful. But when the law was formally stated, to continue these acts became premeditated transgression. Since the law is spiritual and holy and prohibits sinful indulgence, it inevitably excites opposition in rebellious hearts and thus becomes the occasion of stirring up sin and multiplying transgression. If man’s heart were holy, and there were a disposition to do right, law would have no such tendency.

Much more abound. Greek huperperisseuo, “to abound over and above.” The word occurs only here and in 2 Corinthians 7:4. “Abound” and “abounded” earlier in the verse are from the Greek pleonazo, “to be many,” “to multiply.” God permitted sin and allowed it to abound, and then overruled it to bring about the most wonderful display of His glory and grace, so that the benefits of redemption infinitely transcend the evils of the rebellion.