'Righteous' in the Bible

My little children (believers, dear ones), I am writing you these things so that you will not sin and violate God’s law. And if anyone sins, we have an Advocate [who will intercede for us] with the Father: Jesus Christ the righteous [the upright, the just One, who conforms to the Father’s will in every way—purpose, thought, and action].

If you know that He is absolutely righteous, you know [for certain] that everyone who practices righteousness [doing what is right and conforming to God’s will] has been born of Him.

Little children (believers, dear ones), do not let anyone lead you astray. The one who practices righteousness [the one who strives to live a consistently honorable life—in private as well as in public—and to conform to God’s precepts] is righteous, just as He is righteous.

and not be like Cain, who was of the evil one and murdered his brother [Abel]. And why did he murder him? Because Cain’s deeds were evil, and his brother’s were righteous.