The light shines in the darkness,
and the darkness can never extinguish it.

This vers means that the darkness of evil can never overcome the enlightning power of God´s love. In Jesus´ Light we see ourselves as we really are: sinners in need of a savior. But if we follow the path Jesus is lightning for us we won´t stumble in sin and darkness.
Jesus can remove the darkness of sin from our lives. We have to invite Jesus to guide our way so we will never walk in darkness again!

John 1:4