“Therefore by the deeds of the law no flesh will be justified in His sight, for by the law is the knowledge of sin” (Romans 3:20).
Though the intended function of a pair of pliers is not to hammer a nail, that does not mean it has never been tried. One of the ghastly misunderstandings and misuses the Jews made of the Law of Moses was to try to use it to justify sinners. Such was never its intended function.
Justification (i.e., the forgiveness of the guilt of past sins) was never God’s intended function for the Law of Moses. Pharisees (like Saul of Tarsus in his younger days) had completely missed this vital point. Because of this, they devised a religion of justification using brownie points (i.e., extra credit works of merit). They reasoned: If God expected you to fast once a year (on the Day of Atonement—Leviticus 23:27), then fasting twice a week (Luke 18:12) would earn you extra credit (i.e., spiritual brownie points) which would nullify the guilt of your sin and result in a state of justification. As long as you had more extra credit points that guilt marks, you were righteous. Wrong!
Sadly, the whole Roman Catholic system of penance is also predicated on this grotesque falsehood.
The only way to justify a sinner (i.e., a spiritual criminal guilty of a capital offense) is through blood. The soul which sins shall die (Ezekiel 18:4, 20). Therefore, without the shedding of blood, there is no remission (Hebrews 9:22).
As Paul declares in Romans 3:20, the intended function of the Law of Moses was not to justify the guilty in God’s sight. Rather, it was to provide an up close and thorough knowledge (epiginosis) of sin. Fallen humans need to see sin from the perspective of the holy God, whose Lamb would be required and lovingly provided to remedy the horrific mess sin makes.
A failure to understand the original intent of the Law of Moses hinders your appreciation of God and His “indescribable gift” (2 Corinthians 9:15).