Ibn Qayyim al-Jawzeeyah 751 AH (may Allah have mercy on him) said:

أصل كل فتنة انما هو من تقديم الرأي على الشرع و الهوى على العقل

“A root for every fitna (trial/tribulation/etc) only (comes from one) who prefers his opinion over legislation and his desires over intellect.”

Taken from: Ighaatha al-Lahfaan 2/165