Symbolism Wiki

Darkness makes us aware of the stars, And so when dark hours arise, They may hold a bright and lovely thing, We might never have known otherwise. Peter A. Lea

Light represents, hope, good, beauty.  It's the thing that is a match for darkness.  Light can be represented by Jesus, who is the opposite of Satan (aka prince of Darkness).  Many say when you are about to die you see a light in the darkness. They say that means you're about to go to heaven and see Jesus and God.