Sheikh al-Islaam Ibn Taymiyyah said:
Fitnah (trials and tribulations, destruction in the land) does not occur except when the commandments of Allaah are neglected. For He تعالى has commanded us to adhere to the Haqq (truth) and commanded us with Sabr (patience). So fitnah occurs either when the truth is neglected or when patience is neglected.
His student Ibn Al-Qayyim al-Jawziyyah expressed in verse form:
The Haqq (truth) is aided but tested as well, so do not fall in to a state of wonder, for this is the Sunnah (way) of the Most Merciful.
[Mention in “The Islamic Awakening” by Sheikh Muhammad ibn Saalih al Uthaymeen]