A different analogy:
Mr. Paul: I vote because I am 18.
Mr. James: You vote because you are an American citizen, and not merely because you are 18.
Mr. Paul here has not said anything inconsistent with what Mr. James has said. Mr. James has just clarified the statement of Mr. Paul.
And as someone else said, you notice Paul is talking about the law - the OT codes. The new Covenant supersedes the old law, and gives us a different route to God's grace. Catholics completely agree with that.
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