You never know how much you really believe anything until its truth or falsehood becomes a matter of life and death to you. It is easy to say you believe a rope to be strong and sound as long as you are merely using it to cord a box. But suppose you had to hang by that rope over a precipice. Wouldn't you then first discover how much you really trusted it? The same with people.

For years I would have said that I had perfect confidence in X. Then came the moment when I had to decide whether I would or would not trust him with a really important secret. That threw quite a new light on what I called my 'confidence' in him. I discovered that there was no such thing. Only a real risk tests the reality of a belief.

A grief observed - pg 665

Our cause is never more in danger than when a human, no longer desiring, but still intending, to do our Enemy's will, looks round upon a universe from which every trace of Him seems to have vanished, and asks why he has been forsaken, and still obeys.

CS Lewis - Screwtape Letters

A faith without some doubts is like a human body without any antibodies in it. People who blithely go through life too busy or indifferent to ask hard questions about why they believe as they do will find themselves defenseless against either the experience of tragedy or the probing questions of a smart skeptic. A person's faith can collapse almost overnight if she has failed over the years to listen patiently to her own doubts, which should only be discarded after long reflection. 


- The reason for God, Tim Keller, locations 200-210