Do not depend on the hope of results. When you are doing the sort of work you have taken on, essentially an apostolic work, you may have to face the fact that your work will be apparently worthless and even achieve no result at all, if not perhaps results opposite to what you expect. As you get used to this idea, you start more and more to concentrate not on the results but on the value, the rightness, the truth of the work itself.
–Thomas Merton, in a letter to Jim Forest dated February 21, 1966, reproduced in The Hidden Ground of Love: Letters by Thomas Merton (W. Shannon ed. 1993).