Righteousness is “right” doing, in other words doing the things that balance justice.
Since before the days of Noah, even before Enoch and Enosh, the concept of “righteousness” was that of balance. A “righteous” person was someone who used a balanced scale, who used the same measure for everyone including oneself.
More often in ancient times greed and dishonesty could easily be indicated by a merchant who carried two weights and two measuring sticks in his bag. When weighing for his own purchase, he would use the weight that would yield him more product; when weighing to sell, he would use the other weight that would sell less product for more money. The dishonest man would do this so he could dishonestly gain more wealth while appearing to buy and sell with equal standards of measure when he actually, secretly used two standards of measure—one for himself and one for everyone else. This is the meaning of the concept “double standard”.
Using a double standard is something that “righteous” people simply will not allow themselves to do. And, if they ever do, they deeply regret it, resent it, and take steps to prevent themselves from doing it again.
In the Book of Enoch (1 Enoch) and through the Old Testament, this was the initial and archetypal idea of a “righteous” person. The concept of “righteousness” is explained progressively through Scriptue, just as all virtues are explained in greater and greater detail as Bible history unfolds. All law, even sacrificial and priestly laws were built on the concept that they were “just” or “fair” or “righteous” or “balanced” in some way. By the New Testament times, ideas of other virtues are compounded with the idea of “righteousness”, so a “righteous” person also “does good and worthy, noble, and respectable things”. But, when reading about “righteousness” in the Bible, never forget the core, original meaning of “righteousness”. That underlying meaning of “honest and balanced measure” is the dominant idea and basis whenever the Bible mentions “justice” or “righteousness”.
“Righteousness” does not mean “sinlessly perfect”. Every sinner can be a “righteous” [yet also sinful] person—with the conscientious unction and lasting lifestyle habit of using standard measures.
Leviticus 19:35-36, Deuteronomy 25:13-16, Proverbs 11:1,3; 20:23; 21:3, Ephesians 4:25, Colossians 3:9