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

We have already posted, in the answer to question no.
10936, the fatwa of
Shaykh Muhammad ibn Saalih ibn ‘Uthyameen (may Allaah 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 Allaah, 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 Allaah. 

It was narrated from Ibn ‘Abbaas that a black woman came to
the Prophet (peace and blessings of Allaah be upon him) and said: “I
suffer from epilepsy and I become uncovered. Pray to Allaah for me.” He
said: “If you wish, you can be patient and Paradise will be yours, or if you
wish I will pray to Allaah to heal you.” She said, “I will be patient.” Then
she said: “But I become uncovered. Pray to Allaah 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. 

Allaah 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
Allaah we belong and truly, to Him we shall return). This is a promise from
Allaah that He will fulfil. Allaah says (interpretation of the meaning): 

“but give glad tidings to As- Saabiroon (the patient).

156. Who, when afflicted
with calamity, say: ‘Truly, to Allaah 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
Allaah 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 Allaah 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. 

Zaad al-Ma’aad, 4/189. 

The Prophet (peace
and blessings of Allaah 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 Allaah be pleased with him) said: The Prophet (peace and blessings
of Allaah 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 Allaah has decreed for the Muslim
is good.”

Narrated by Muslim, 2999. 

Trials and
calamities are a test, and are a sign of Allaah’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 Allaah is the highest description. According
to a saheeh hadeeth: “The greatest reward comes with the greatest trial.
When Allaah 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-Albaani. 

We should not hate the trials that Allaah has decreed for us.
Al-Hasan al-Basri (may Allaah 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 Allaah knows best.