As soon as we ask what faith is and what sort of mistreatment of faith causes doubt, we are led to the first major misconception about doubt-the idea that doubt is always wrong because it is the opposite of faith and the same thing as unbelief. What this error leads to is a view of faith that is unrealistic and a view of doubt that is unfair.
In Two Minds: The Dilemma of Doubt & how to Resolve it (ed. IVP Books, 1976)