In Romans 4 and 5, Paul talks about how righteousness was credited to Abraham and us by faith in Jesus Christ. Many interpret several of these passages as Paul rejecting the “law of the prophets” because of these verses:
For the promise to Abraham or his posterity, that he should inherit the world, did not come through [observing the commands of] the Law but through the righteousness of faith. [Gen. 17:4-6; 22:16-18.]If it is the adherents of the Law who are to be the heirs, then faith is made futile and empty of all meaning and the promise [of God] is made void (is annulled and has no power).For the Law results in [divine] wrath, but where there is no law there is no transgression [of it either].Therefore, [inheriting] the promise is the outcome of faith and depends [entirely] on faith, in order that it might be given as an act of grace (unmerited favor), to make it stable and valid and guaranteed to all his descendants–not only to the devotees and adherents of the Law, but also to those who share the faith of Abraham, who is [thus] the father of us all. (Romans 4:13-16)
For sin shall not [any longer] exert dominion over you, since now you are not under Law [as slaves], but under grace [as subjects of God’s favor and mercy].
What then [are we to conclude]? Shall we sin because we live not under Law but under God’s favorand mercy? Certainly not!
[To be sure] sin was in the world before ever the Law was given, but sin is not charged to men’s account where there is no law [to transgress].Yet death held sway from Adam to Moses [the Lawgiver], even over those who did not themselves transgress [a positive command] as Adam did. Adam was a type (prefigure) of the One Who was to come [in reverse, the former destructive, the Latter saving]. [Gen. 5:5; 7:22; Deut. 34:5.] (Romans 5:13-14)
Rather than viewing the law as something that reveals sin, mankind began to follow the laws, thus replacing God’s grace, and righteousness, with our own righteousness. No man, could ever measure up the righteousness of Christ and therefore, no man could ever pay the debt to sin. This is what God was trying to tell us with the Law. He merely allowed us to understand that only He, was able to forgive our sins by sending His son to pay our debt.