The Transfiguration is about Peter–and imperfection.

And here is Peter, awe struck at his teacher enshrined in light—God, he’s sure that this is it, this is perfection, this is the moment they’ve all been waiting for–and, then, he sees the two men turn, Moses and Elijah, turn away from Jesus–and he cries, “Wait! It is good for us to be here! Let us build three dwellings—let us stay—let us be here, in this moment in this glory–please—don’t leave me.”