Water and oil, though they don't mix, CAN coexist. White and black can coexist. They can even mix and become gray. But light and darkness cannot coexist. Wherever there is light, darkness flees.
Light always drives away darkness.
There's life in light. Most forms of photosynthesis release oxygen as a byproduct which is what WE live on. There's life in light. Professor Ake Daun of Stockholm University, says that people are like plants. We are phototropic, meaning we bloom in sunlight.