‘And this is the judgment: the light has come into the world, and people loved the darkness rather than the light because their works were evil. For everyone who does wicked things hates the light and does not come to the light, lest his works should be exposed. But whoever does what is true comes to the light, so that it may be clearly seen that his works have been carried out in God.’ (John 3:19–21, ESV)

However, these four problems of pride, religion, intellect, and spirituality are only part of the reason why Nicodemus could not trust Christ. So, in his fourth answer, Jesus turns to the illustration of light and dark to appeal to our M - his morality. He uses this imagery of light and darkness because light is a revealer of things, as truth is a revealer things. This he couldn’t hide from. This is a most powerful statement made by Jesus and is well illustrated by C.S. Lewis. Lewis tells the story  of how on one sunny day he was standing in his dark tool shed and noticed a sunbeam shining through a crack between the door and the roof. He comments that the only thing that he could see was the beam of light and the thousands of tiny dust particles that it picked up as it shone a beam of light across the shed. As he approached the crack and allowed the beam of light to cover his eyes, instantly the darkness around him disappeared and a whole new picture was available to him: green leaves moving on the branches of a tree outside and beyond that, some 90 million miles away, the sun itself. Looking along the beam, says Lewis, and looking at the beam are two very different experiences.

What Jesus is saying to Nicodemus is that the light is beaming as a prism of light into the world and marking out a division between what is holy and what is not. As one steps into that beam it reveals in terrible detail the sinfulness of our hearts and the enormous need we have for a Deliverer. When standing in that beam there is no one who is able to say that their own goodness matches the goodness of Christ. And with that truth, the biggest reality of all sets in: that Jesus, the source of light and very Light Himself (cf. John 8:12) became as darkness itself so that we might shine like the stars. (cf. Philippians 2:15). The extent to which we rest on the finished work of Christ upon the cross for our sins will be extent to which the prism of Christ is displayed more readily in our lives.