John Calvin Commentary James 1:23

"For if any one is a hearer of the word and not a doer, he is like unto a man beholding his natural face in a mirror:" — James 1:23 (ASV)

He is like to a man. Heavenly doctrine is indeed a mirror in which God presents himself to our view; but so that we may be transformed into his image, as Paul says in 2 Corinthians 3:18. But here he speaks of the external glance of the eye, not of the vivid and efficacious meditation which penetrates into the heart. It is a striking comparison, by which he briefly intimates that a doctrine merely heard and not received inwardly into the heart avails nothing, because it soon vanishes away.