From the Bible:
Book of Isaiah in the Bible, Chapter 9, tells us:
The people that walked in darkness have seen a great light: they that dwell in the land of the shadow of death, upon them hath the light shined.
From the Bhagavad Gita, fifth Chapter:
That darkness of the soul is chased by light
Splendid and clear shines manifest the Truth
As if a Sun of Wisdom sprang to shed
Its beams of light.