Will a person be rewarded for any calamity such as disease or an accident that befalls him?
Question

Witchcraft and the evil eye are trials from Allah. Will a person be rewarded if he is afflicted by either of them? Will a person be rewarded for any calamity such as disease or an accident that befalls him, or are there things that Islam says must be followed in order to attain the reward?
Praise be to Allah.We have already posted, in the answer to question no. 10936, the fatwa of Shaykh Muhammad ibn Saalih ibn ‘Uthyameen (may Allah have mercy on him), which states that the calamities for which a Muslim may be rewarded are those which he bears with patience and seeks the reward from Allah, may He be blessed and exalted. 
Undoubtedly being afflicted by the evil eye and witchcraft are some of the greatest calamities that may befall a Muslim, for their effects on the mind, heart and body of the victim may be serious. Bearing that with patience will bring a great reward from Allah. 
It was narrated from Ibn ‘Abbaas that a black woman came to the Prophet (peace and blessings of Allah be upon him) and said: “I suffer from epilepsy and I become uncovered. Pray to Allah for me.” He said: “If you wish, you can be patient and Paradise will be yours, or if you wish I will pray to Allah to heal you.” She said, “I will be patient.” Then she said: “But I become uncovered. Pray to Allah that I will not become uncovered.” So he prayed for her. Narrated by al-Bukhaari, 5652; Muslim, 2576. 
The calamities that befall a person and affect him or his wealth or his family are not completely bad, rather they may result in a lot of good for a person. 
Allah has told us in His Book of that which may reduce the impact of the calamity on a person and encourage him to seek reward, namely patience and saying Inna Lillaahi wa inna ilayhi raaji’oon (Truly, to Allah we belong and truly, to Him we shall return). This is a promise from Allah that He will fulfil. Allah says (interpretation of the meaning): 
“but give glad tidings to As- Saabiroon (the patient).
156. Who, when afflicted with calamity, say: ‘Truly, to Allah we belong and truly, to Him we shall return.’
157. They are those on whom are the Salawaat (i.e. who are blessed and will be forgiven) from their Lord, and (they are those who) receive His Mercy, and it is they who are the guided ones” [al-Baqarah 2:155-157]
Ibn al-Qayyim said: 
This phrase is one of the greatest means of dealing with calamity and is one of the most beneficial in this world and in the Hereafter. It comprises two great principles which, if a person understands them properly, will bring him consolation for the calamity that has befallen him: 
1 – That the person, his family and his wealth all belong to Allah in a real sense; they have been given to him as a loan, and if they are taken from him, that is like the lender taking back his property from the borrower. 
2 – The person will ultimately return to Allah his Lord. He will inevitably leave this world behind and come before his Lord on his own as He created him the first time, with no family, no wealth, no tribe, rather with good deeds and bad deeds. If this is how he started and is how he is going to end, then how can he rejoice over what he has or grieve over what he does not have? Thinking about how he began and how he will end is the best remedy for this problem. "Zad al-Ma’ad, 4/189"
The Prophet (peace and blessings of Allah be upon him) has told us that bearing hardships and calamities with patience is something that can only be done by those who have achieved true faith. 
It was narrated that Subhayb al-Roomi (may Allah be pleased with him) said: The Prophet (peace and blessings of Allah be upon him) said: “How wonderful is the affair of the believer, for his affair is all good, and this applies to no one except the believer. If something good happens to him, he gives thanks and that is good for him, and if something bad happens to him, he bears it with patience, and he will be rewarded for that, so everything that Allah has decreed for the Muslim is good.” Narrated by Muslim, 2999. 
Trials and calamities are a test, and are a sign of Allah’s love for a person. They are like medicine: even if it is bitter, you offer it despite its bitterness to one whom you love – and for Allah is the highest description. According to a saheeh hadeeth: “The greatest reward comes with the greatest trial. When Allah loves a people He tests them. Whoever accepts that wins His pleasure but whoever is discontent with that earns His wrath.” Narrated by al-Tirmidhi, 2396; Ibn Maajah, 4031; classed as saheeh by Shaykh al-Albani. 
We should not hate the trials that Allah has decreed for us. Al-Hasan al-Basri (may Allah have mercy on him) said: Do not hate the trials that befall you or the calamities that happen to you, for they may be something that you hate but it leads to your salvation, and there may be something that you love, but it leads to your doom. 
And Allah knows best.