Limited to Lk. 23:41; 1 Cor. 15:34; 1 Thess. 2:10; Tit. 2:12; 1 Pet. 2:23, the Greek adverb “dikaios” meant “uprightly,” “justly,” “properly,” “agreeably to right.”
One of the crucified thieves near Jesus said their punishment was proper. In 1 Cor. 15:34 the meaning is “properly, as is right” (Thayer, p. 151). Christians are to live “righteously” on the earth (1 Thess. 2:10; Tit. 2:12).
Found more than 75 times in the New Testament, the Greek adjective “dikaios” meant “righteous,” “just,” “upright,” “impartial.” This adjective first occurs in Mt. 1:19; Joseph was a “righteous” man. God sends rain on the “just” and the unjust (Mt. 5:45). There is a “righteous man’s reward” (Mt. 10:41). Some are outwardly “righteous” (Mt. 23:28) but inwardly corrupt. Pilate’s wife used this adjective to describe Jesus (Mt. 27:19). The saved are commanded to make “righteous” judgments (Jn. 7:24). The “just” shall live by faith (Rom. 1:17). It is not the hearers of the law who are “just” before God; it is the “doers” (Rom. 2:13). There is “none righteous” (Rom. 3:10). Jesus is a “righteous” judge (2 Tim. 4:8). The fervent prayers of “righteous” people can avail much (Jas. 5:16). The eyes of the Lord are over the “righteous” (1 Pet. 3:12). Lot was a “just” man (2 Pet. 2:7). The last place this adjective is used in the New Testament is Rev. 22:11.