If we lived in the sun, perhaps there would be no shadows. But we have left the sun and come down to earth, and the earth revolves around the sun, thus creating the alternation of light and shade.
Since we are outside the sun, we have to accept this alternation: day and night, light and dark, activity and rest, good and evil.
Not only must we accept it, but we must also know how to use it.
How do you use the night? Marvellously – you sleep, you do nothing, and in the morning when you wake up, you have regained all your strength, your body has rid itself of its waste and you are once again ready to begin work.
So why can’t you also learn to use evil, darkness and difficulties? To use evil, you must integrate it, that is, you must incorporate it into your work as raw material, just as a chemist uses all substances, however toxic. Everything can be useful.