Everyone experiences difficult times in his or her life. These difficulties frustrate, distress or irritate the majority of people who are far removed from the morality prescribed in the Qur'an. Therefore, they easily become anxious, tense and irritable. Not having faith in the perfection inherent in the destiny ordained by God, they do not seek the blessings, or the good in that which they experience. In fact, because they are without faith, every moment they spend only turns out to seem against them. In this manner, encumbered by trouble and distress, they proceed with the rest of their lives.
Believers, however, know that difficulties are brought about by God to test man. They are aware that these difficulties serve to distinguish the true believers from "those having a disease in their hearts", those who are not sincere in their beliefs. That is because, in the Qur'an, God makes it plain that He will test believers to reveal who it is that are truthful:
Or did you imagine that you were going to enter the Garden without God knowing those among you who had struggled and knowing the steadfast? (Surah Al 'Imran: 142)
God would not leave the believers in that [state] you are in [presently] until He separates the evil from the good... (Surah Al 'Imran: 179)
In further regard to this issue, God provides the following example, which took place during the time of the Prophet Muhammad (saas):
What assailed you on the day the two armies met was by God's permission, so that He would know the [true] believers, and so that He would know the hypocrites... (Surah Al 'Imran: 166-167)
The verse above is self-explanatory. In the time of the Prophet (saas), Muslims faced hardships, and suffered trying conditions. Yet, as the above verse also indicates, what the Muslims endured was by God's Will, and served to reveal those who were the hypocrites, who tried to cause harm to believers. That is, everything ultimately turned out in favour of the believers.
Muslims, who aware of the lessons stated in these verses, consider an incident that seems to be evil, or a moment of difficulty, as an opportunity by which their sincerity, loyalty to their Lord, and faith, is put to the test. Never do they forget that difficulties or blessings are to test them. On the contrary, for their nobleness and submission to Him, God changes what seems evil to the advantage of His true servants.