My dear children, I am writing this to you so that you will not sin. But if anyone does sin, we have an advocate who pleads our case before the Father. He is Jesus Christ, the one who is truly righteous.

Since we know that Christ is righteous, we also know that all who do what is right are God’s children.

Dear children, don’t let anyone deceive you about this: When people do what is right, it shows that they are righteous, even as Christ is righteous.

So now we can tell who are children of God and who are children of the devil. Anyone who does not live righteously and does not love other believers does not belong to God.

We must not be like Cain, who belonged to the evil one and killed his brother. And why did he kill him? Because Cain had been doing what was evil, and his brother had been doing what was righteous.