Shaykh Yasir Qadhi delves on verse 147 of Surah Al-Nisa, where Allah asks the believers a rhetorical question - "What would Allah do with your punishment if you are grateful and believe?"
This Ayah lays the foundation as to why this world is one of pain and suffering and also what leads mankind to become atheists. This Ayah illustrates that there is pain and suffering because of a higher wisdom. Nothing happens without a cause and reason.
Of the causes we are in pain and suffering are as follows:
We are not thankful when we are in a blessed state.
To remove arrogance from within us.
In the humbling of ourselves when in calamity, we discover the necessity and sweetness of Dua.
We have to earn our place in Jannah with whatever meagre good we can do in this world. Allah will give you with much more than what you have earned.
To alleviate the pain of the Akhirah.