But when people keep on sinning, it shows they belong to the Devil, who has been sinning since the beginning. But the Son of God came to destroy these works of the Devil.
Those who have been born into God's family do not sin, because God's life is in them. So they can't keep on sinning, because they have been born of God.
So now we can tell who are children of God and who are children of the Devil. Anyone who does not obey God's commands and does not love other Christians does not belong to God.
References for 1 John 3:10