O you, who spends his lifetime disobeying his Lord, no one amongst your enemies is wicked to you more than you are to yourself
Ibn Qayyim Al-JawziyyaThere is no joy for the one who does not bear sadness, there is no sweetness for the one who does not have patience, there is no delight for the one who does not suffer, and there is no relaxation for the one who does not endure fatigue.
Ibn Qayyim Al-JawziyyaThe ibtilaa' (testing) of the believer is like medicine for him. It cures him from illness. Had the illness remained it would destroy him or diminish his reward and level (in the hereafter). The tests and the trials extract these illnesses from him and prepare him for the perfect reward and the highest of degrees (in the life to come).
Ibn Qayyim Al-Jawziyya