Indeed it is so.
The shadow or dark side of a person creates the balance of the light aspects of the person. Both are present to create growth and balance as responses indicate preferences through choice.
Without contrast there is no feeling of growth in your outer experience. Examine how you feel when you are addressing something that creates growth in your life. Your preferences through beliefs and feelings create outer circumstances and provide continual opportunities to expand what you thought you knew and move into a broader perspective.
Enjoy the contrast in your life as it provides a new way to see what you are feeling deep within yourself. What feelings have you created that serve the highest good for all. If you would like to change a feeling it’s as easy as choosing a new point of view.
What lies in between the outer and inner world of realities? It’s the unseen glue that allows all realities to be expressed. One thing is certain: For every view there is an opposite.
Practice: Follow the times in the day when your feeling less than ideal. In that moment of realization, think of something that makes you smile. Focus on how good that feeling is as you continue to imagine or feel what it felt like when you were happy. Note how your body and mind feel better after this simplistic awareness exercise. Repeat often.