Whether your faith is that there is a God or that there is not a God, if you don’t have any doubts, you are either kidding yourself or asleep. Doubts are the ants in the pants of faith. They keep it awake and moving.
Faith is better understood as a verb than as a noun, as a process than a possession. It is on-again-off-again rather than once-and-for-all. Faith is not being sure where you’re going, but going anyway. A journey without maps.
–Frederick Buechner, Wishful Thinking: A Seeker’s ABC (from the entries on “Doubt” and “Faith”)