"No one who is born of God practices sin, because His seed abides in him; and he cannot sin, because he is born of God.  By this the children of God and the children of the devil are obvious; anyone who does not practice righteousness is not of God, nor the one who does not love his brother."

John continues to work with the 'children' metaphor.  Here, he tries to remind us that our spiritual walk is a journey - not an instant fix.

John says that if you are connected with God then you do not sin.  In effect, he says that this is because we are God's children.  That there is no sin in God and therefore His children will grow up to be just like Him.

Children take time to grow.

The child of God will eventually grow to be exactly like their Father.

John lets us know about our future while reminding us that we have a long way to go.

If you pursue righteousness - pursue long term relationship.