Ibn al-Qayyim (rahimahullah) said: ‎Du'aa is one of the most beneficial cures and it is the enemy of fitnah (evils, calamities and trials), it wards it off and treats it, prevents it to happen and cures it if it happens. Du'aa is the weapon of the believer. [Ibn al-Qayyim (rahimahullah), ad-Da' wad Dawaa, Pg. 11]