Q:
Can disrespecting the Divine Decree put you past the pale of Islam?
A:
In the Name of Allah, the All-Merciful, the Mercy-Giving.
All praise is due to Allah. Peace and blessings be upon His Messenger Muhammad.
Belief in qadar (divine decree and preordainment) is an essential constituent of Islamic faith. When the Messenger of Allah (peace and blessings be upon him) was asked by Angel Gabriel, “What is iman (faith)?” He answered, “It is to believe in Allah, His angels, His Books, His Messengers, the Last Day, and the qadar, both good and evil.” (Muslim)
A Muslim has to believe that Allah knew everything about His created beings before their creation (all that happened and all that will happen) and that He wrote this down in a Heavenly Preserved Writ. Everything thus comes to pass as already written.
Therefore, disbelief in or disrespect of qadar sends one outside the fold of Islam. The Messenger of Allah (peace and blessings be upon him) said, “No one attains belief until he believes in four: To testify that there is no true god but Allah and that I am the Messenger of Allah whom he sent with the truth, to believe in death and resurrection after death and to believe in qadar.” (Al-Tirmidhi) When the famous Companion Abdullah ibn `Umar was told about a group of people at his time who denied the divine decree and preordainment he swore that, “Should anyone of them have as much gold as the size of Mount Uhud and spend it [in the cause of Allah], Allah would not accept it until he believes in qadar.” (Muslim)
Allah knows best.