A high character might be produced, I suppose, by continued prosperity, but it has very seldom been the case. Adversity, however it may appear to be our foe, is our true friend; and, after a little acquaintance with it, we receive it as a precious thing - the prophecy of a coming joy. It should be no ambition of ours to traverse a path without a thorn or stone.

The Complete Works of C. H. Spurgeon, Volume 36: Sermons 2121-2181 (ed. 2015)