The Bible is uses the example of dark and light to symbolize the ways of God (light) and the ways of evil (dark). Darkness contributes to our lost-ness, and confusion. Light allows us to see things: clearly, distinctly, openly, truthfully, and eternally. Jesus said John 8:12; " I am the light of the world. Whoever follows me will never walk in darkness."
When my kids were little we always made sure we had “night lights” on so they wouldn’t stumble if they awoke in the dark. If we are Christ followers we can always have His light reflected in us. It can keep us and others from falling.