It seems to be a paradox, but one of the signs that Allah loves His slave is when He afflicts him with hardship, including illnesses. This statement may appear counter intuitive, but viewed through the eyes of a Muslim, there is a logic behind it, which we will come to.
By contrast, when Allah does not love someone, He increases the person's immersion in dunia (the material life). We may believe that prosperity and continuous good health is a sign of acceptance from Allah, but in reality, it can pose a great fitnah (trial) from Allah. This is known as istidraj, when Allah plies a person with material comforts such that he is lulled into a false sense of security and stops safeguarding his akhirah (the hereafter).
The successful and wealthy who have forgotten Allah are examples of that. Man's predisposition is that when things are rosy, he tends to drift from Allah. They feel invincible, and consequently live their lives as if they would never die or meet their Lord. With them, good health can be a trial, and not a blessing. We may have come across such people: they are neglectful of Allah – and then one day they die without warning – with no time to repent.
Illness makes one humble
Regardless of background, illnesses have a humbling effect on people. A virus, tumour, stroke, paralysis or injury, can turn the world upside down. Suddenly, they are faced with a situation which is out of their control, and are confronting their own mortality. Especially humbling is when the illness causes them to be dependent on others – people, medication or equipment - for the most basic functions such breathing and going to the bathroom.
Any person, when the pain or illness is so severe, will find that all his material accomplishments - career, house, car – become irrelevant. Even sexual desire disappears! Instead, he becomes wrapped in his own fragility. This is the normal reaction for most people when they wait for that chilling diagnosis or feel uncontrollable pain rip through their bodies.
Illnesses are a way of Allah giving you a gentle nudge (and in some cases, a push), to remind you to turn to Him. For it is during this state of vulnerability that most people turn to their Creator for help, it is during this time that the spiritual senses are awakened in that instinctive awareness to seek a higher power who holds the cure.
A lucky few will heed the reminder to turn to Allah. This is the blessing behind the illness. The same way that Allah sometimes takes away everything from you in order that you have no one to turn to but He, Allah sometimes takes away your physical health to regenerate your spiritual one.
Illnesses are a Mixed Blessing
Allah in His Mercy, does not subject his servants to suffer without compensating them. If we feel the pain of disease, remember that Prophets and Messengers actually used to have it worse:
Ibn Mas`ud (RA): I visited the Prophet (peace be upon him) when he was suffering fever. I said, "You seem to be suffering greatly, O Messenger of Allah.'' The Prophet (peace be upon him) replied, "Yes, I suffer as much as two persons.'' I said, "Is that because you have a double reward?'' He replied that that was so. (Bukhari & Muslim)
Further, Ayoub AS suffered years of chronic disease – one so appalling that his flesh fell from his bones, maggots crawled from his putrid wounds and the stench of his flesh was so disgusting that his community banished him to live in a rubbish dump. In the cases of normal human beings, such symptoms would usually result in a quick but painful death, but Ayoub AS bore the anguish for eighteen years.
The hadith above continues:
"No Muslim is afflicted by a harm, be it the pricking of a thorn or something more (painful than that), but Allah thereby causes his sins to fall away just as a tree sheds its leaves". [Bukhari & Muslim].
This encouragement applies to the believers only. It means that he must react within the prescribes of Islam – with patience, gratitude, contentment with Allah's decree and total submission to Allah. The illness then becomes a blessing. With every ache, pain, fever and discomfort that is borne, forgiveness follows. With every agony that is endured, the bad deeds are erased from his records.