Doubt is named doubt because it resembles truth. As for lovers of Allah, their conviction serves them as light and the direction of the right path serves as their guide; while the enemies of Allah, in time of doubt call to misguidance in the darkness of doubt and their guide is blindness. One who fears death cannot escape it nor can one who fears for eternal life secure it.
Imam Ali, Nahjul Balagha – Sermon 38