Allah swt may test a slave with: - health and sickness , wealth and poverty , success and failure , etc

...We are putting all of you to a test by passing you through bad and good conditions,... ( Quran 21 : 35 )

Or think you that you will enter paradise without such (Trials) as came to those who passed away before you? They were afflicted with severe poverty and ailments... (Qur’an 2 : 214)

You (believers) will certainly be tested by the loss of your property and lives... (Qur'an 3 : 186)

Narrated Ibn `Abbas: The Prophet (pbuh) went to visit a sick bedouin. When the Prophet (pbuh) went to a patient, he said,

"Do not worry, if Allah will, it will be expiation (for your sins):"...

(Sahih al-Bukhari Hadith 5656)

37. Abu Sa`id and Abu Hurairah (May Allah be pleased with him) reported that the Prophet (PBUH) said:

"Never a believer is stricken with a discomfort, an illness, an anxiety, a grief or mental worry or even the pricking of a thorn but Allah will expiate his sins on account of his patience". [Al-Bukhari and Muslim].

38. Sahih Bukhari Volume 7, Book 70, Number 551: Narrated 'Abdullah: I visited Allah's Apostle while he was suffering from a high fever. I said,

"O Allah's Apostle! You have a high fever." He said, "Yes, I have as much fever as two men of you." I said, "Is it because you will have a double reward?" He said, "Yes, it is so. No Muslim is afflicted with any harm, even if it were the prick of a thorn, but that Allah expiates his sins because of that, as a tree sheds its leaves."

1726. Jabir (May Allah be pleased with him) reported: The Messenger of Allah (PBUH) visited Umm Sa'ib (or Umm Musaiyyab) and asked her,

"What ails you O Umm Sa'ib (or Umm Musaiyyab)? You are shivering.'' She replied: "It is a fever, may Allah not bless it!'' He said to her, "Do not revile fever, for it cleanses out the sins of the sons of Adam in the same way that a furnace removes the dirt of iron.'' [Muslim].

35. Sahih Bukhari Volume 7, Book 70, Number 555: Narrated 'Ata bin Abi Rabah: Ibn 'Abbas said to me,

"Shall I show you a woman of the people of Paradise?"

I said, "Yes." He said, "This black lady came to the Prophet and said, " I get attacks of epilepsy and my body becomes uncovered; please invoke Allah for me." The Prophet said (to her), 'If you wish, be patient and you will have (enter) Paradise; And if you wish, I will invoke Allah to cure you.' She said, 'I will remain patient,' and added, 'but I become uncovered, so please invoke Allah for me that I may not become uncovered.' So he invoked Allah for her."

Ayub AS ka Sabar...

The Prophet Hazrat Ayub A.S. was blessed with health, wealth, and family. Yet Allah wanted to test his faith and eventually all was taken.

His wealth vanished, he lost his family and he got terribly sick which lasted for 18 long years. He got involved in a disease where all his body got covered with sores. Yet he had such a strong faith in Allah that he did not become hopeless.