Important texts of Islam include The Qu'ran, the Five Pillars, and the Hadith.
The Qa'ran tells every Muslim how they can live a good life that leads them to have a better next life.
It's purpose is intended in the verses: ". . . Indeed, there has come to you light and a clear book from Allah; With it Allah guides him who fill follow His pleasure into the ways of safety and brings them out of utter darkness into light by his will and guides them to the right path." (V: 15-16)
It is necessary for each Muslim to live by The Five Pillars to show devotion to worshiping Islam.
The Hadith includes the traditions the prophet Muhammad lived by that all Muslims should practice. His sayings and methods were to be studied first in order to abide by the instruction of Allah.