Two Hundred Questions and Answers on the Islamic Creed–Haafidh Al-Hakami
In The Name of Allaah, The Most Merciful, The Bestower of Mercy
What is the first obligation upon the slaves (of Allaah)?
The first thing obligatory upon the slaves of (Allaah) is to know the affair for which Allaah created them; and for which He took a covenant from them, sent His Messengers and revealed His Books to them. And for that reason, He (Allaah) created the worldly life, the afterlife, paradise and hell; and because of it Al-Haaqqah- The inevitable (i.e. the day of judgment) will surely be established and Al Waaqi-ah—The Event (i.e. the day of judgement) will take place. And due its affair the scales (of good and bad deeds) will be erected and the scrolls of (good and good deeds) will be laid out, and there will be the wretched and the blessed. And due to it the light (of Islaam and guidance to the straight path) is distributed and to whomsoever Allaah gives no light, he has no light.
[Source: 200 Su-aal Wa Jawaab Fil Aqeedah Al-Islaamiyyah: page: 21]