The Transfiguration was a mountaintop event in which Jesus was transformed and became dazzling white, in a manner that suggested his future glory.  Peter, James, and John witnessed Jesus’ transfiguration; Moses and Elijah appeared on the mountain and talked with Jesus.  The event, which is related in Matthew 17, Mark 9, and Luke 9, is celebrated in many churches at the end of the season of Epiphany, the Sunday before Lent.