Henri Nouwen like many great spiritual directors was a letter writing. This is an excellent compilation of his letters on the spiritual life.
Letter to a young couple
“I was fascinated by the contrast in your letter between your response to ‘Clowning in Rome'(Henri’s book, published in 1979, about solitude, celibacy, contemplation and prayer) and your most urgent needs. I seriously believe that some of the places about which I talk are placed which can help you to feel rooted without being ‘settled with title, salary and prestige’. The solution- I think- is not moving to another outer place but to another inner place. The great challenge remains to find the eternal in the midst of the temporary, to touch what remains in what passes and to love the ever living God in the love of the quickly passing family of people”
Henri Nouwen, Love, Henri: Letters on the Spiritual Life, page 35