Because it is not of faith — He does not believe it lawful and, in all these cases, whatsoever is not of faith is sin — Whatever a man does without a full persuasion of its lawfulness, it is sin to him.
Related Commentaries of Romans 14:23
Romans 14:23
23 And he that doubtethf is damned if he eat, because he eateth not of faith: for whatsoever is not of faith is sin.