Zeljko Tadic Posted 9 months ago Lesley Hazleton: The doubt essential to faith I totally don't agree with the speaker. All those things she ascribed to crusaders actually describe religious books like bible or koran. These books are claimed to give us all the answers for all of the life's problems and we are not to doubt the writings even for a second. Doubt is not the core of faith. Faith is blind. End of story.