Light is an important symbol at Christmas time. Christians often refer to Jesus as the ‘Light of the World’. Light is associated with goodness and understanding (enlightenment).
Christians believe that Jesus did not just bring goodness and understanding - because he was the incarnation of God he was that goodness and understanding itself. The light of his very being dispels the darkness of ignorance; in John’s Gospel Jesus says:
“I am the Light of the World. No follower of mine shall wander in the dark; he shall have the light of life.” (John 8.12 NEB)
On the right is a very famous painting by William Holman Hunt depicting Jesus as 'The Light of the World'.