To teach people that when Jesus was transfigured on the mountain and the disciples saw His glory; they saw who Jesus truly is. We can catch a glimpse of Jesus' glory as we spend time alone with Him and time with other christians, but one day we will see His glory in full.
To challenge people to respond to Jesus' call to follow Him, by showing them that with Jesus in their lives they will be spiritually safe and fruitful but without Him they will not.
To share the good news of Christmas; that Jesus, the Saviour of the world has come and to encourage people to take a look for themselves at Jesus, the baby in the crib.