From `Abdul`Aziz ibn `Abdullah ibn Baz to our honorable brother (...), may Allah protect him!
Assalamu `alaykum warahmatullah wabarakatuh (May Allah's Peace, Mercy, and Blessings be upon you!)
I have received your letter. May Allah guide you and grant you success! You have mentioned in your letter that you are about to write a book on the Madhhab (belief) of the righteous Salaf (righteous predecessors) with regard to Divine Decree which many people have erred when discussing. You have also expressed your wish that we write a brief treatise in this regard.
On this occasion, I ask Allah (Glorified and Exalted be He) to guide you to the Truth. It is firm resolution and blessed determination. May Allah grant you the ability to clarify the Truth and clear up doubts! He is the Most Generous!
I am pleased to participate in this outstanding work.
The Qur'an, the Sunnah, and the Ijma` (consensus) of the Salaf (righteous predecessors) indicate that it is Wajib (Obligatory) to believe in Divine Decree, good or bad. It is one of the six fundamentals of Iman i.e. belief. The Iman of a person is never complete unless he believes in the Divine Decree.
Know you not that Allâh knows all that is in the heaven and on the earth? Verily, it is (all) in the Book (AlLauhalMahfûz). Verily that is easy for Allâh.
No calamity befalls on the earth or in yourselves but it is inscribed in the Book of Decrees (AlLauh AlMahfûz) before We bring it into existence. Verily, that is easy for Allâh.
Verily, We have created all things with Qadar (Divine Preordainments of all things before their creation as written in the Book of Decrees AlLauh AlMahfûz).
Iman is to believe in Allah, His Angels, His Book, the meeting with Him, His Messengers, the Day of Resurrection, and destiny.
Iman is to believe in Allah, His Angels, His Books, His Messengers, the Last Day, and destiny; good and evil.
Scholars (may Allah be merciful with them) stated that believing in the Divine Decree has four levels:
First: To believe that Allah (Glorified be He) knew everything before its existence through His eternal Knowledge. He knew the measures, lifespan, and the livelihood of His creation.
Second: To believe that Allah (Exalted be He) has recorded everything; good and bad, good deeds and sins, and lifespan and provision.