Another very important factor that clouds people's minds is their distrust of Allah, in other words not submitting to the fate Allah has decreed for them. One who doesn't trust Allah has forgotten that Allah has infinite wisdom and controls every situation and every creature in the universe. And because of this, as with all the other factors that veil the mind, he cannot analyse things clearly or fully see realities.
However, Allah watches over and protects all beings. Whether they are aware of this or not, Allah creates events according to a decree and with these events He tests people. So, Allah creates every event a person faces throughout his life with a motive and for a good reason. This is how Allah warns people on this matter:
Allah alone has knowledge of what the heavens and the earth conceal; to Him all things shall be returned. So worship Him and put your trust in Him. Your Lord is not unaware of what you do. (Surah Hud: 123)
… It may be that you hate something when it is good for you and it may be that you love something when it is bad for you. Allah knows and you do not know. (Surat al-Baqara: 216)
One who believes these verses and comprehends that behind every incident there is a hidden motive and benefit for him, is one who has trust in Allah. Even if he faces a situation, which at first sight seems to his disadvantage, he knows that this will bring him good in this world and in the next and he acts on this knowledge. Because he evaluates incidents with full trust in Allah, his reasoning and judgement are in perfect shape, and as a result he can make sensible evaluations. On the other hand, one who has no faith in Allah forgets that Allah creates events in order to test him and so becomes totally distant from rationalism.
We can explain the great difference between these two people with an example. Let's say that a factory goes on fire and the owner of the factory forgets that this situation is controlled by Allah and doesn't think that there must be a benefit in this situation for him, so he begins to distrust Allah. And, one who doesn't trust Allah cannot think straight or take the necessary precautions or in any other way, act sensibly. For example, not being calm and composed can cause the otherwise extinguishable fire to grow. He loses time by being panic and grief-stricken and making a fuss instead of putting out the fire, saving his property, or calling the fire brigade. After the fire, instead of taking measures against future fires so that it won't ever happen again, he occupies himself with useless thoughts, such as "how and why did it happen, I wish it had not happened, or if I had done so-and-so it wouldn't have happened". 
One, who trusts Allah, never becomes hopeless or sad, even if he loses everything he has. This person knows that Allah can take away a blessing He gave and that He does this to test people's trust in Him. With a clear consciousness, he tries to take care of the damage as soon as possible and takes the most swift and sensible precautions. He doesn't waste his time in panicking, worrying, or losing hope. Furthermore, without losing any time after such an event, he tries to make up for the damage by taking the most effective precautions possible so that it will not recur.
When it comes to the property he has lost, because he knows that the only owner of wealth is Allah, he is peaceful and at ease. He trusts Allah with all his heart and he prays for Him to give him more than what he has lost. And he is happy to know that he will be rewarded much more for his trust in Allah in the Hereafter.
Our Prophet (saas) explained this issue in the following example, "If you put your whole trust in Allah, as you ought, He most certainly will satisfy your needs, as He satisfies those of the birds. They come out hungry in the morning, but return full to their nests." (Tirmidhi)
