Also @ Christian_gnosis, in the context of the verses you posted, was Paul not referring to the circumcision law? This law was classified as a cleansing ritual and a covenant between Abraham and God. It did not of itself justify anyone. the Apostle Paul does not seem to be referring to any other...
Topic Writer, you also seem to think that Christians who observe God's Spiritual law seem to think that the law "justifies" them. No, they clearly do not believe that. As the verse you just posted verifies, the law cannot justify anyone nor do the commandment keepers believe that the law...
@ Topic Writer, you're showing a contradiction in the apostle Paul's writings if you're going to ignore the verses below, or do you have an explanation for them?:
Romans 3:31, "Do we then make void the law through faith? God forbid: yea, we establish the law."
Romans 7:14, "For we know...