The play of light and dark. Contrasts. It is the difference between the two that catches your eye. If all were dark or all were light, there would be no movement, no growth. You would stagnate. Again we exhort you to embrace your challenges. It is through the contrast between what you perceive as goodness and light and that which you perceive as negativity and darkness that you move and grow.
Change is a good thing. Embrace it. You can have and enjoy more light than darkness, but do not eschew the darkness. It is only through the contrast that you know and appreciate the difference.