Sin is transgression—transgression of the law, for the law of Moses indicates what sin is and which sacrifices were necessary for each transgression. But given that this law came much later than Adam, how can one speak about sin before Moses?

Paul anticipates this argument and proceeds to address it in Romans 5:13–14. It is an important point for him, for it is precisely the universality of sin that requires that there be a single Mediator for all of humanity.

Paul is convinced that sin existed before the law, for why else did people die before the law? He writes: Yet death reigned from Adam to Moses, even over those whose sinning was not like the transgression of Adam (Romans 5:14ab). Adam’s progeny did not eat of the tree of the knowledge of good and evil; yet they all died. It is therefore evident that they were just as guilty before God as Adam and Eve were, although they were guilty in a different way. Their death proved their guilt while simultaneously proving that the law of God already existed before the law of Moses came into effect.¹

 Paul can say, for sin indeed was in the world before the law was given (Romans 5:13a). This is because the law itself did not bring sin into the world, but the law of Moses simply identified and revealed what those sins are. It is, as it were, the accounting that revealed the debt. Sin already existed, but sin is not counted where there is no law (Romans 5:13b). In the King James Version the verb ellogein is rendered as imputed (but sin is not imputed when there is no law). From the point of view of modern English, it may seem as though such a translation indicates that sin was not considered as such before the time of Moses,  however when considering the semantics of the older English, the King James Version clearly meant that the arrival of the law provided a more specific account of an already existing universal guilt. In other words, the law does not introduce the guilt or debt of man to God, but only calculates that debt.²