Romans 3:5-8   God shows His great mercy and glory by saving us through faith in Him.  By man’s convoluted logic, our unrighteousness increases God’s glory by allowing Him to show more grace.  In that case, God would be doing wrong to Himself by judging us.  Apparently some were using that weird argument against salvation by grace through faith.  And throwing the works of Judaism and the law back into the mix.

Romans 3:20  “…by…the law…shall no flesh be justified…by the law is the knowledge of sin”
Core of Paul’s argument.  We are metaphysically unable to keep the law.  Plus, by the time we learn of it, it shows us that we have already sinned.  There is no provision in the law to remove sin besides death.  Sacrifices only covered them up, did not pay for them.

Romans 3:25  “…for the remission of sins that are past, through the forbearance of God”

Romans 3:28  “…a man is justified by faith without the deeds of the law”

I hope you enjoy reading and studying His word.  May it accomplish what He desires.  Please feel free to comment or post questions.  Thanks for reading!