The passage in the lectionary today, Mark 9:2-9, comes in the context of Jesus’ question to the disciples; ‘Who do you think I am?’, and his preparation of the disciples for the coming crucifixion.  The disciples hear God speak about his Son.  The transfiguration shows them God ‘glorifying’ his Son – the ‘metamorphosed’ Jesus reveals God’s glory.  Paul uses the same Greek word to speak of believer being  ‘transformed’ into the likeness of Christ.