Abu Hurairah narrates that the Prophet (saws) said: "When Allah wants to be good to someone, He tries him with some hardship." [Book Sahih Bukhari]
When passing through a mountain pass, a bedouin once came across an old man who was blind and who seemed to be afflicted with various ailments all over his body. It was clear that he was wasting away. He was even paralyzed and was constantly forced to remain in a seated position. The Bedouin could clearly hear him say, “All praise is for Allah, Who has kept me safe from ailments with which He has tesed many among His creation; and He has indeed preferred me over many among those that He created.”
“My brother!” exclaimed the bedouin. “What have you been saved from? By Allah, I think that you have been afflicted with every single kind of ailment!”
“Go away from me,” said the old man, as he raised his head. “Do I not still have a tongue with which I can pronounce His Oneness, and with which I can remember Him every single moment? And do I not still have a heart with which I can know Him?”
These words of the old man were enough for the bedouin to repent to Allah for his sins and ask Him for forgiveness.