Incredulity
From BiblePortal Wikipedia
Charles Buck Theological Dictionary [1]
The withholding our assent to any proposition, notwithstanding arguments sufficient to demand assent.
See Duncan Forbes's piece, entitled, Reflections on the Sources of Incredulity with regard to Religion, and Casaubon on Credulity and Incredulity.
Webster's Dictionary [2]
(n.) The state or quality of being i/credulous; a withholding or refusal of belief; skepticism; unbelief; disbelief.