If we say openly that we have done wrong, he is upright and true to his word, giving us forgiveness of sins and making us clean from all evil.

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 have knowledge that he is upright, it is clear to you that everyone who does righteousness is his offspring.

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.

We must not be like Cain who was a child of the evil one, and butchered his brother. And why did he butcher him? Because his own actions were wicked and his brother's upright.