How is man supposed to interrelate with his fellow man and with God?
Man is to interrelate with his fellow man and with God through love. The Creator Himself knew when He created mankind in the garden that this is how man would have to interrelate. Loving another fulfills the law, so love is the governing principle for both human relationships and relationship with God.
Les explains that they come from the Creator Himself, and He knew when He created mankind in the garden in the first place that this is how man would have to interrelate with his fellow man as well as with God Himself. The key point Les emphasizes is that when you have loved another, you have fulfilled the law.