Originally Posted by paradise786
"Nothing repels Divine Decree except du'a, and nothing increases one's life-span except good deeds." (Authentic, reported by al-Tirmidhi and al-Hakim from Salmaan, and is in Saheeh al-Jaami')
This hadeeth informs us in no uncertain terms that the only way we can repel Divine Decree is through the means of du'a. So it is possible that some unpleasant matter has been prerordained for us, but only if we do not make du'a to avert it from us. So if du'a is made, then this matter will not be fulfilled, whereas if du'a is left, misfortune will occur.
Another narration in al-Tirmidhi supports this:
"There is no Muslim on the face of the earth that asks Allah for anything except that Allah gives it to him, or averts from him a similar evil, as long as he does not ask for something evil or for breaking the ties of kinship." (Authentic, narrated by al-Tirmidhi from ubaadah ibn Saamit, in Saheeh al-Jaami')
From this narration, the benefits of du'a are made clear. Not only is a person rewarded for making a du'a, but it is also the cause of repelling an evil that was destined for him, and in obtaining the good that he was expecting.
From: Du'a, Weapon of the Believer, by Aby Ammaar Yasir Qadhi.
And Allah knows best.