This document discusses the purpose, power, privilege, and promise of light based on several Bible passages. It argues that light is meant to shine for others and overcome darkness, not be hidden. Those who walk in the light have fellowship with God and are cleansed of sin. In contrast, those who love darkness avoid exposure of their deeds. The document encourages readers to let their light shine and not hide from spiritual light, promising that sharing light with others increases it while hoarding it allows it to die out.