James 4:11-12 Speak According To The Law.
James, as much as any other author in the bible, spent an extensive amount of time and words addressing what should and should not characterize our speech. Here he again issues a warning, given specifically to believers concerning their fellow believers. “Do not speak evil of one another, brethren (v. 11a). Peter gives us some examples of evil speaking. “Therefore, laying aside all malice, all deceit, hypocrisy, envy, and all evil speaking, as newborn babes, desire the pure milk of the word, that you may grow thereby” (I Pet. 2:1-2). He who speaks evil of a brother and judges his brother, speaks evil of the law and judges the law” (vv. I Pet. 2:1-2). Just as Peter pivots away from “evil speaking,” to its opposite, “the pure milk of the word,” in the same way James pivots to the law.
“He who speaks evil of a brother and judges his brother, speaks evil of the law and judges the law” (v. 11b). The reason this is the case, is because it is the law which forbids speaking evil of a brother, as James has already made abundantly clear (Ch. 3). To speak evil of a brother is to bear false witness against him (Ex. 20:16; Dt. 5:20). It is also a failure to “fulfill the royal law” (2:8; Lev. 19:18). Anyone who thus judges and speaks evil against a brother, is saying that they are above the law, and in fact sitting in judgment of it and God Himself. It also means one is obviously not a doer of the word either (v. 11c). What James is referring to is the kind of judging that is evil speaking, and therefore contrary to the law (Cf. Mt. 7:1-5). Ultimately all people will be judged by God (v. 12).