Generally, whatever disturbs the peace of mind of a human being in unusual situation, removes the curtain from the real morality of that human being. In normal condition, the human being is like a still water in a pool, due to lack of motion, whatever is mixed with water is settles at the bottom and a very clear water can be seen.
But when a piece of wood is entered in the water and it is shaken, then you can see how much dirt is in the same water. Many individuals in normal condition refer to their heart and soul and see it the same as that clear water in the pool and they are neglectful of the time when the new condition arises and causes their settled evil characteristics appear and in this way it will prove how much impurities have existed in their souls [1].
[1] The Book Collection of Martyr Motahhari, Vol. 25, page 59.
source : Shafaqna