The fact that we love God Himself, and obey His commands, is a proof that we love God's children.
»Thus I command you to love one another.«
And by this we may know that we know Him–if we obey His commands.
But whoever obeys His Message, in him love for God has in very deed reached perfection. By this we can know that we are in Him.
As for us, we know that we have already passed out of death into Life–because we love our brother men. He who is destitute of love continues dead.
And the command which we have from Him is that he who loves God must love his brother man also.