From the first moment that he sets foot on this inner path until the last one when he has finished it, he will at intervals be assailed by tests which will try the stuff he is made of. Such trials are sent to the student to examine his mettle, to show how much he is really worth, and to reveal the strength and weakness that are really his, not what he believes are his. The hardships he encounters try the quality of his attainment and demonstrate whether his inner strength can survive them or will break down; the sufferings he experiences may engrave lessons on his heart, and the ordeals he undergoes may purify it. Life is the teacher as well as the judge.
-- Perspectives > Chapter 2: Practices for the Quest > # 19