Little children, make sure no one deceives you. The person who practices righteousness is righteous, in the same way that Jesus is righteous.
The person who practices sin belongs to the devil, because the devil has been sinning since the beginning. God's Son appeared for this purpose: to destroy the works of the devil.
Those born from God don't practice sin because God's DNAa remains in them. They can't sin because they are born from God.
This is how God's children and the devil's children are apparent: everyone who doesn't practice righteousness is not from God, including the person who doesn't love a brother or sister.
This is the message that you heard from the beginning: love each other.
Don't behave like Cain, who belonged to the evil one and murdered his brother. And why did he kill him? He killed him because his own works were evil, but the works of his brother were righteous.