From Brandon Sanderson's Mistborn series:

"Certainly, my situation is unique," Sazed said. "I would say that I arrived at it because of belief."

"Belief?" Vin asked.

"Yes," Sazed said. "Tell me, Mistress, what is it that you believe?"

Vin frowned. "What kind of question is that?"

"The most important kind, I think."

Vin thought, then shrugged. "I don't know what I believe."

"People often say that, but I find it is rarely true."