Bliss belongs to the bondsman who strives for Allah against his own nature and passions: he who then defeats his passion wins Allah's pleasure, and the one whose intellect leaves behind the self which commands evil through his striving jihad, submission and humility in the service of Allah has won a great victory. There is no veil between the bondsman and Allah which is darker or more desolate than that of self and passion; there is no better weapon to fight and destroy them than total need of Allah, glory be to Him, fear, hunger, thirst in the day and wakefulness at night.
When a person possessing these traits dies, he dies a martyr. If he lives according to the straight path, his end will take him to the greatest pleasure of Allah.
And [as for] those who strive hard for Us, We will most certainly guide them in our ways, and Allah is most surely with the doers of good. (29:69)
When you see someone striving harder than you, upbraid yourself, and reproach yourself in order to encourage yourself to do more. Put a halter of command and rein of prohibition on the self, and carry on as if you were a trainer who does not let his mount take a step unless it is completely correct.
The Messenger of Allah used to pray until his feet were swollen. He would say, 'How can I not be a thankful slave?' The Holy Prophet wanted to make his community consider this so that they would not neglect striving, toil, and discipline in any state. If you were to experience the sweetness of worshipping Allah, to see it’s blessing and be illuminated by its light, you would not be patient without it for a single hour, even if you were to be cut to pieces. No one turns away from it without being denied such benefits of protection and success from Allah as were attained by his forefathers.
Rabi' ibn Khuthaym was asked why he did not sleep at night. 'Because I fear to spend the night in sleep,' he replied.