'Righteous' in the Bible

My little children, I'm writing these things to you so that you might not sin. Yet if anyone does sin, we have an advocate with the Father Jesus, the Messiah, one who is righteous.

Since you know that he is righteous, you also know that everyone who practices righteousness has been fathered by God.

Little children, don't let anyone deceive you. The person who practices righteousness is righteous, just as the Messiah is righteous.

Do not be like Cain, who was from the evil one and murdered his brother. And why did he murder him? Because what he was doing was evil and his brother's actions were righteous.