Without light, there would be no darkness.
Without darkness, there would be no light.
What makes a good picture? Why is art so appealing? If you take much time to think about it, the answer is probably because of contrast. This concept is so deeply fundamental to everything around us - from being able to see, to hearing noise. If the world were static, and no contrast existed, what would there be to see? The world would be one shade of grey and sound would be a monotonous buzz. Contrast is essential to everything we take for granted. When dark and light are beside each other, it is easy to see the difference, to determine the line between them.
What if there were no bad in the world? What if we never experienced a struggle within our beings? Maybe you think life would be easier - and maybe it would be - but would it be better? Would it be as beautiful? The hard times make us grateful for the good times; and the evil in the world (and inside of us) makes it possible for us to recognize the good. If the world were all good, perhaps it would only look grey to us. Perhaps we would not be able to distinguish the raw purity of its light.
It may seem difficult to be grateful for the hard times, for the evil people, for the struggle inside. But work to find gratitude in your heart, because if the bad did not exist, perhaps the good wouldn't either.