“At the present moment two things about the Christian religion must surely be clear to anybody with eyes in his head. One is, that men cannot do without it; the other, that they cannot do with it as it is.”

Newsigned Books (June 2014) http://www.newsignedbooks.com/nader-nadernejad.html

Professor Van Helsing to Dr. Seward
Dracula (1897)
Context: You reason well, and your wit is bold, but you are too prejudiced. You do not let your eyes see nor your ears hear, and that which is outside your daily life is not of account to you. Do you not think that there are things which you cannot understand, and yet which are, that some people see things that others cannot? But there are things old and new which must not be contemplated by men's eyes, because they know, or think they know, some things which other men have told them. Ah, it is the fault of our science that it wants to explain all, and if it explain not, then it says there is nothing to explain. But yet we see around us every day the growth of new beliefs, which think themselves new, and which are yet but the old, which pretend to be young, like the fine ladies at the opera.

Source: Intercourse (1987), Chapter 7

The Unsearchable Riches of Christ

Source: Growing Up Absurd (1956), p. 189.

1950's, On Being a Graphic Artist', 1953
Context: I do indeed believe that there is a certain contrast between, say, people in scientific professions and people working in the arts. Often there is even mutual suspicion and irritation, and in some cases one group greatly undervalues the other. Fortunately there is no one who actually has only feeling or only thinking properties. They intermingle like the colors of the rainbow and cannot be sharply divided. Perhaps there is even a transitional group, like the green between the yellow and the blue of the rainbow. This transitional group does not have a particular preference for thinking or feeling, but believes that one cannot do without either the one or the other. At any rate, it is unprejudiced enough to wish for a better understanding between the two parties... It is clear that feeling and understanding are not necessarily opposites but that they complement each other.

As quoted in Have Fun with American Heroes : Activities, Projects, and Fascinating Facts (2005) by David C. King, p. 82; this is also attributed to Dawson Trotman in Through Her Eyes : Life and Ministry of Women in the Muslim World (2005) by Marti Smith, p. 116
Disputed

Variant: If a man has to say trust me, Gogu conveyed, it's a sure sign you cannot. Trust him, that is. Trust is a thing you know without words.
Source: Wildwood Dancing