Os Guinness said this quote

Interestingly, God's remedy for Elijah's depression was not a refresher course in theology but food and sleep... Before God spoke to him at all, Elijah was fed twice and given a good chance to sleep. Only then, and very gently, did God confront him with his error. This is always God's way. Having made us as human beings, He respects our humanness and treats us with integrity. That is, He treats us true to the truth of who we are. It is human beings and not God who have made spirituality impractical.

~ Os Guinness

The question the doubter does not ask is whether faith was really useless or simply not used. What would you think of a boy who gave up learning to ride a bicycle, complaining that he hurt himself because his bicycle stopped moving so he had no choice but to fall off? If he wanted to sit comfortably while remaining stationary, he should not have chosen a bicycle but a chair. Similarly faith must be put to use, or it will become useless.

~ Os Guinness

To come to faith on the basis of experience alone is unwise, though not so foolish as to reject faith altogether because of lack of experience ... the quality of a Christian's experience depends on the quality of his faith, just as the quality of his faith depends in turn on the quality of his understanding of God's truth.

~ Os Guinness

We are not wise enough, pure enough, or strong enough to aim and sustain such a single motive over a lifetime. That way lies fanaticism or failure. But if the single motive is the master motivation of God's calling, the answer is yes. In any and all situations, both today and tomorrow's tomorrow, God's call to us is the unchanging and ultimate whence, what, why, and whither of our lives. Calling is a 'yes' to God that carries a 'no' to the chaos of modern demands. Calling is the key to tracing the story line of our lives and unriddling the meaning of our existence in a chaotic world.

~ Os Guinness