John 8:12

When Jesus spoke again to the people, he said, “I am the light of the world.  Whoever follows me will never walk in darkness, but will have the light of life.”
How do we prevent falling into darkness?  Follow Him.  Listen to Him.  Believe Him.  Do what He says.  Rest in Him.  Allow His perfect light and life to fill you so that you look no other place.  He is all we need!