If we follow Christ, we will not walk in darkness  -  John 8:12

Then spake Jesus again unto them, saying, I am the light of the world: he that followeth me shall not walk in darkness, but shall have the light of life.

Naturally speaking, the world is in the darkness of sin, ignorance, and aimlessness. In contrast, Jesus is the light of the world. Apart from Him, there is no deliverance from the darkness of sin, no guidance along the way of life, no knowledge to the meaning of life, and no understanding of the reality of eternity. Jesus promised that anyone that followed Him, would not walk in darkness, but have the light of life.