Castiel does not quite know what to say to that.

The silence stretches on as he watches the workers wrestle the next beam into place (using some less than holy language).

"They build them because they need them," he says at last. "We do not. They," he indicates the men, "might say that we are the fortunate ones in that respect."

Angels do not have to wonder if the Kingdom of Heaven does, in fact, exist.