"​The people who have walked in darkness have seen a great light"                    ​ (Isaiah 9:2a)                  

   
"But this is the judgment: the light has come into the world, but people loved the darkness rather than the light..." (Jesus in John 3:19a) 

Yet "If we walk in the light as [God] is in the light, we are in fellowship with one another, and the blood of Jesus cleanses us from all sin."         (1 John 1:7)