From the Confucian Analects:
“Tzu-Lu (one disciple of Confucius) asked about serving the spirits [of the dead], the Master said, “While you are not able to serve men, how can you serve [their] dead spirits?” [Tzu-Lu added], “I venture to ask about death?” He was answered, “While you do not know life, how can you know about death?”
From James Legge, 1870. The Chinese Classics: A Translation by James Legge. New York: Hurd and Houghton, pp. 57-58.