The parallels between light and good vs. darkness and evil are stated throughout scripture. Isaiah laments people who try to make you believe that good is evil and evil is good, and who put darkness for light.
Light = Good; Darkness = Evil
The Light of Life
Things on Earth are patterned after things in the heavens. God has withdrawn his presence from the world and dwells in a realm of light, while we are here on Earth toiling through an ever encroaching darkness.
Matty's Paradigm 