Allah (God) Almighty, is most merciful and compassionate, without any doubt. Yet his actions can not be fully comprehended by our incompetent minds. What simplifies this issue is that we all agree that Allah is fair, just, wise and knowing. That means whatever he-Almighty- does, is with a legitimate purpose although we may not be able to understand, just why. For example, a caring and loving doctor and father may be forced to amputate the leg of his only son. There is no doubt that this father loves his son. Yet his action was for the sake of this beloved son, although it may seem cruel to those who do not understand the circumstances. Allah –Almighty – has the greater and higher example, and it is not to any of his creatures to question his doings as it is mentioned in Sura 21 verse 23 (interpreted means: “He cannot be questioned for His acts, but they will be questioned (for theirs)”.
It is a Muslim’s belief that suffering of pain, hunger, tragic accidents etc, are due to one’s sins, for Allah wants this suffering to erase these sins which were made by this Muslim. Allah says in Sura 42 verse 30 interpreted means: “Whatever misfortune happens to you, is because of the things your hands have wrought, and for many (of them) He grants forgiveness”. It is also apparent that man in times of crisis gets closer to Allah and starts repenting, while in times of ease and comfort he is far from remembering the blessings of Allah and he uses these gifts and blessings in committing sin after sin.
Allah -Almighty- has shown man the path of good and evil, and he gave him the power and will to choose. Therefore, man is accountable to his deeds and the punishment he receives for them, for life in this world is merely a test, but the results are to be known in the hereafter and Allah knows best.
Courtesy - Islam Q&A
Diseases
Diseases are one of those things in our lives reminding us of how weak we truly are. Our perfectly protected bodies can be severely impaired by a tiny bacteria or a virus that is invisible to naked eye. Actually a little thinking will make us understand that it is surprising for our bodies to be so heavily affected by a bacteria. It is so, because Allah created our body with flawless protection systems, especially our immune system. It can be comfortably called a ‘strong army’ fighting against the enemies of our body. However, despite all these protective systems, humans can’t help but fall ill very frequently. This should make us understand that Allah could have created us in such a way that we would never get ill. Viruses, bacteria would not affect us at all, or these tiny ‘enemies’ specially prepared would not have existed at all. However, any person, at any time, can find himself struggling with a health problem for no apparent reason. For example, one virus entering the body through a small cut on the skin can spread throughout the body in a short amount of time. No matter how advanced the technology is, the simplest virus can overpower us very easily.
These are not far-fetched scenarios, they can happen to anyone at anytime; this should make everyone ponder on these facts thoroughly. Just like all other weaknesses, diseases also are specially created by Allah for us. Man has a tendency to be arrogant and conceited, forgetful of his weaknesses. These diseases help man see and understand his weaknesses and also see the true, undesirable nature of this life.
The diseases are tests created by Allah so that Muslims will long for heaven, contemplate the blessings, the gift of health granted to them by Allah and give thanks to Him and also realize how weak they are, which should make them surrender to Allah with all their hearts.
Man tends to take many things for granted in life. However, all those things in this world that we love so much are simply the blessings created by Almighty Allah.
For example, many people forget that it is a huge blessing that every morning we are able to get up and stand and walk easily on our feet. However, a tiny problem in one foot could cause a big problem, impeding daily activities. A person who has a foot ache will then be able to better appreciate the thousand steps he takes during the day without feeling any pain.
A devout Muslim takes this and many other seemingly unimportant things as opportunities to give thanks to Allah and get closer to Him. He remembers that Allah gave him a great blessing by making him a healthy person. He also sees one more time that it is Allah that gives the disease and only Allah can heal him, and therefore turns to Allah for recovery. Every moment when there is a feeling of pain, he remembers Allah and keeps his heart focused on Allah all the time.
" He who created me and guides me;
He who gives me food and gives me drink;
and when I am ill, it is He who heals me;
He who will cause my death, then give me life;
He who I sincerely hope will forgive my mistakes on the Day of Reckoning.
My Lord, give me right judgment and unite me with the salihun;
and make me highly esteemed among the later peoples;
and make me one of the inheritors of the Garden of Delight " [Quran 26: 78-85]
He who gives me food and gives me drink;
and when I am ill, it is He who heals me;
He who will cause my death, then give me life;
He who I sincerely hope will forgive my mistakes on the Day of Reckoning.
My Lord, give me right judgment and unite me with the salihun;
and make me highly esteemed among the later peoples;
and make me one of the inheritors of the Garden of Delight " [Quran 26: 78-85]
Diseases make us understand that being attached to this world is utterly pointless. They also show us that everything we have is a part of our test. in this way we can understand that we are only the poor servants of Allah and can be easily defeated and even killed by germs. Allah created us, and He protects us from all kinds of dangers surrounding us. No matter how much one tries to think otherwise and try to persuade himself that he is powerful, he can never help or even protect himself if Allah doesn't wish it. If Allah wills it, Allah can give one diseases and create other weaknesses in his body that will perfectly make him understand his frailty (The condition of being weak and delicate) .
This life is a place of testing created by Allah. Every person is responsible for spending his life in a way that pleases Allah and is tested constantly for this purpose. Those who are following the orders of Allah and display good morals will deserve to live in heaven forever. However, those who continue to be arrogant and prefer a couple of decades of this life over eternal heaven will not be able to rid themselves from weaknesses, troubles and problems both in this world and in the hereafter.
"Be sure we shall test you with something of fear and hunger, some loss in goods or lives or the fruits (of your toil), but give glad tidings to those who patiently persevere" [Quran 2:155]