THESAURUS
disbelieve
be skeptical, deny, discredit, distrust, doubt, eschew, gag on, misbelieve, mistrust, negate, not accept, not admit, not believe, not buy, not fall for, not go for, not swallow, question, refuse to admit, refuse to believe, refuse to credit, reject, resist believing, scoff, scorn, scout, suspect, unbelieve
ROGET THESAURUS
disbelieve
Irreligion
VB
be irreligious,
disbelieve, lack faith, doubt, question, dechristianize.
Doubt
VB
disbelieve, discredit, not believe, misbelieve, refuse to admit, refuse to believe, doubt, be doubtful, doubt the truth of, be skeptical as to, diffide, distrust, mistrust, suspect, smoke, scent, smell a rat, have doubts, harbor doubts, entertain doubts, suspicions, have one's doubts, demure, stick at, pause, hesitate, scruple, stop to consider, waver, hang in suspense, hang in doubt, throw doubt upon, raise a question, bring in, call in question, question, challenge, dispute, deny, cavil, cause a doubt, raise a doubt, start a doubt, suggest a doubt, awake a doubt, make suspicion, ergotize, startle, stagger, shake one's faith, shake one's belief, stagger one's faith, stagger one's belief.