John Gill Commentary James 2:12

"So speak ye, and so do, as men that are to be judged by a law of liberty." — James 2:12 (ASV)

So speak you, and so do
Both words and actions should be taken care of; it becomes men to observe what they say, and what they do; for both sinful words and works are transgressions of the law, and will be brought to judgment; every idle word, as well as every evil work, both open and secret, men must give an account of in the day of judgment: wherefore it is incumbent on them so to behave,

as they that shall be judged by the law of liberty :
(See Gill on James 1:25) with which compare (Romans 2:12Romans 2:16) . Heathens will be judged by the law of nature, Jews by the law of Moses, and those who live under the Gospel dispensation, according to the Gospel of Christ.