In order to understand the Muslim perspective on suffering, one needs to first explore the much larger question of the purpose of the creation of humankind according to Islam.
The following is an excerpt from a
webpage:
Why did God create mankind?
"{Remember] when your Lord extracted from the loins of Adam’s children and their descendents and made them testify [saying] : ‘Am I not your Lord?’ They said: ‘Yes, we testify to it.’ [This was] in case you say on the Day of Judgment: ‘We were unaware of this.’ Or you say: ‘It was our ancestors who worshiped others besides God and we are only their descendants. Will you then destroy us for what those liars did?’ " … The Holy Qur’an, Chapter 7, Verses 172-3
The Prophet Muhammad (pbuh) explained that when Allah created Adam (pbuh), He took from him a covenant at a place called Na’maan on the 9th day of the 12th month. He then extracted from Adam all of his descendants who would be born until the end of the world, generation after generation, and spread them out before Him to take a covenant from them also. He spoke to them, face to face, making them bear witness that He was their Lord.
Consequently, every human being is responsible for belief in God, which is imprinted on each and every soul. It is based on this inborn belief that Allah defined the purpose of humankind’s creation:
"I have created the jinn and humankind only for My worship" … The Holy Qur’an, Chapter 51, Verse 56
Thus, the essential purpose for which humankind was created is the worship of God and the term ‘
worship’ here means not just to perform acts like prayer and fasting, but rather it means to consciously do all the things that pleases God like being kind to and helping others in need, taking care of other creations like trees and animals… and also to leave the things that He has forbidden.
However, the Almighty is not in need of human worship. He did not create human beings out of a need on His part. If not a single human worshiped God, it would not diminish His glory in any way, and if all mankind worshiped Him, it would not increase His glory in any way.
God is perfect. He alone exists without any needs. All created beings have needs. Consequently, it is humankind that needs to worship God.
The question concerning the purpose of mankind’s creation may be expanded to include the world in which they live. The question would then be, “Why did God create human beings in this world?” Again, the answer to this question can easily be found in the final revelation, Chapters al-Mulk and al-Kahf:
"[It is He] who created death and life to test which of you is best in conduct; and He is the Mighty, the Forgiving" … The Holy Qur’an, Chapter 67, Verse 2
"Surely I have created all that is on earth as its ornaments that I may test which of them is best in conduct." … The Holy Qur’an, Chapter 18, Verse 7
Thus, the purpose for the creation of human beings in this world is to test their conduct. This world of life and death, wealth and poverty, sickness and health, was created to sift out the righteous souls from the evil souls. The tests serve to confirm on the Day of Judgment that those going to hell deserve it and those going to paradise only got there by God’s grace.