Jesus is light for those who are blind - both blind to the truth and blind to who Jesus truly is. The Pharisees were looking for a Messiah who would come in glory and power - they were "theologians of glory." But Jesus the Messiah is revealed in the crucifixion, when the light of the world seems to be overtaken by darkness. John is a "theologian of the cross" who shows that Christ crucified ("the Son of Man lifted up") is the surest revelation of who God is in Jesus.