Imaam Ibnul Qayyim (رحمه الله تعالى) said:
"Whoever ponders upon the state of affairs of the world will find that every affair of rectification is due to Tawheed, singling out Allaah in worship and obedience to His Messenger (Muhammad). And every evil in the world, trial, affliction, scarcity (in livelihood), being overpowered by an enemy and other than that is due to (our) opposition to the Messenger and call to other than (the way of) Allaah and His Messenger.
"Whoever ponders upon the state of affairs of the world will find that every affair of rectification is due to Tawheed, singling out Allaah in worship and obedience to His Messenger (Muhammad). And every evil in the world, trial, affliction, scarcity (in livelihood), being overpowered by an enemy and other than that is due to (our) opposition to the Messenger and call to other than (the way of) Allaah and His Messenger.