2:20

O empty man: James directs his words to an imaginary opponent who believes that faith alone is enough. The apostle Paul uses a similar rhetorical technique in his letters. (Ro 2:1; 9:20; 1Co 15:36) One reference work states that this was a common method of argument in ancient times. James calls this hypothetical man “empty”; he lacks accurate knowledge of God and a true understanding of his Word. By addressing an imaginary opponent, James does not offend his readers but helps them to avoid adopting wrong views.

faith without works is useless: In the preceding verse, James has made the point that even the demons have a form of belief in God; they acknowledge that he exists and shudder at his power to destroy them. (See study notes on Jas 2:19.) But James’ readers knew well that the demons are far from having the kind of faith that pleases God. Whatever belief in Jehovah the demons have is worthless; it will never move them to do anything good or righteous.​—See study note on Jas 2:14.

useless: This term translates a Greek word that could literally be rendered “idle.” Without works, faith is inactive and unprofitable; it is as unproductive and wasteful as a laborer who refuses to do the work he was hired for.​—Compare Tit 1:12, where the same Greek word is rendered “idle.”