The festival celebrates the revelation of the eternal glory of the Second Person of the Trinity, which was normally veiled during Christ’s life on earth. This is the Christian commemoration of the occasion upon which Jesus took Peter, James, and John, up on a mountain, and both Moses and Elijah appeared. Jesus' then "transfigured": his face and clothes became white and shining as light (Mark 9:2–13; Matthew 17:1–13; Luke 9:28–36).