Have you ever wondered about the purpose of mankind’s creation? What’s the reason for our existence, and what role do we play in this worldly life?
People who believe in Allah understand that the creation of this world and mankind occurred only by His will. However, in a world where there is a purpose to everything, it is natural to ponder over the intention behind this creation. 
One thing is unquestionable – Allah never creates anything in vain. Allah Subhanahu wa Ta'ala Himself says in the Holy Qur’an:
“Then did you think that We created you uselessly and that to Us you would not be returned?” – (Al-Mu’minun: 115)
A non-believer may believe the objective of this life is to pursue pleasure and collect wealth. However, a believer knows none of this will benefit him in the long run. 
As stated in the Qur’an in multiple places, Allah SAW did not create us to be necessarily comfortable. Rather, He created man to obey and serve Him. This is not for the benefit of the Creator but for the benefit of His Creation.
For instance, Allah SAW says in the Qur’an:
“And I did not create the jinn and mankind except to worship Me. I do not want from them any provision, nor do I want them to feed Me.” – (Adh-Dhariyat: 56-57)
A man’s acts of worship for Allah are not automatic as they are for the majority of His Creations. Therefore, whom we worship and how we pray is a result of our own choice and efforts, and this is what entitles us to Allah’s honor and rewards.
Allah SWT has provided every living and inanimate element of His Creation with a clear path and guidance. His revelation (the Qur’an) instructs humanity on how to lead a purposeful life and what things to avoid, along with their reasons. It informs a man about what is expected of him and the results of his continued positive efforts.  
Allah also revealed the many ways of worshipping through the Prophet Muhammad SAW. These acts of worship, in combination with the guidance provided to us in the Qur’an and Sunnah, are what enable us to fulfill the purpose of His Creation. That is, to obey Him and live by His rules.
One who fails to comply with His orders not only stays restless in this world but also loses any chance of gaining Jannah in the Hereafter.
Consequently, this life is meant to be a purposeful test for all believing Muslims because it determines the outcome and the permanent position in their next life.