In a healthy relationship between significant others, the two individuals are interdependent, like the sun and the moon. The moon doesn't need the sun to rise and the sun doesn't need the moon to set, but they do need each other to activate the universe.
In our lives, we will have better relationships if we foster this sort of interdependence—a situation where each person strives individually to become a more loving, Light-filled human being. In this scenario, each person in the relationship has his or her own nature, but both find that their journey through life is more beautiful and offers more opportunities for spiritual growth when taken together.