The Transfiguration of Jesus has to be a moment of revelation that extends and exists beyond the mountaintop experience. Otherwise, it will only justify glory, power, and privilege. And so, our call to preach this Sunday has to be grounded in the ways in which God grounds God’s very self in transfiguration. God has chosen to reveal God’s self in ways that are breathtaking, miraculous, wondrous. Why? Because we have a tendency to tame God, to think that God will adjust to our many needs, to think that God will conform to our ideals.
When the Transfiguration becomes a sort of embarrassment for the church, an example of the ways in which the church hopes for glory, an argument for Jesus’ divine identity, a chance to wax nostalgic about mountaintop experiences, well then, it will cease to matter. Make it matter by preaching what it is — no ordinary mountaintop experience.
Read it all; quoted by yours truly in the early morning sermon (my emphasis)