I really liked the following quote which is quoted by Aldous Huxley in his book The Perennial Philosophy:

“Ga-San instructed his adherents one day: ‘Those who speak against killing, and who desire to spare the lives of all conscious beings are right. It is good to protect even animals and insects. But what about those persons who kill time, what about those who destroy wealth, and those who murder the economy of their society? We should not overlook them. Again, what of the one who preaches without enlightenment? He is killing Buddhism.”

From “One Hundred and One Zen Stories