I slept with faith and found a corpse in my arms on awakening; I drank and danced all night with doubt and found her a virgin in the morning. Aleister Crowley
One of the painful things about our time is that those who feel certainty are stupid, and those with any imagination and understanding are filled with doubt and indecision. Bertrand Russell
Whenever conscience speaks with a divided, uncertain, and disputed voice, it is not the voice of God. Descend still deeper into yourself, until you hear nothing but a clear, undivided voice, a voice which does away with doubt and brings with it persuasion, light, and serenity. Henri-Frédéric Amiel
If we lose that sacred fire - if we let it be smothered with doubt and fear - then we shall reject the destiny which Washington strove so valiantly and so triumphantly to establish. Franklin D. Roosevelt
To be certain of the existence of God and to be certain of the nonexistence of God seem to me to be the confident extremes in a subject so riddled with doubt and uncertainty as to inspire very little confidence indeed. Carl Sagan
Obey your soul, have perfect faith in yourself. Never think of yourself with doubt or distrust, or as one who makes mistakes. Wallace D. Wattles