Jesus took Peter, John and James and went up the mountain to pray. While he was praying his face changed in appearance and his clothing became dazzling white.
There are many times in the Gospels when we are told Jesus went up a mountain or to a lonely place to pray Prayer was an essential part of his life, even during the very busy days of ministry. And during prayer he was transformed. On this particular occasion it was a visible change. But prayer, being in the presence of God, always transforms. It transfigured Jesus, and we too can share something of that experience whenever we pray. Turning to God is the most powerful thing we can do.