Al-Qadar (Divine Decree) is an Arabic word meaning Allah’s predestination of measurements and sustenance of everything and everyone, according to His Knowledge and Wisdom.
Belief in the Divine Decree of Allah is one of the pillars of faith. The faith of a slave will be incomplete unless he believes in the Divine Decree, whether good or bad. This belief cannot be completely fulfilled unless the servant of Allah believes in four things:
1. Knowledge: The belief that Allah’s Knowledge encompasses everything, every matter, major or minor, and the time frame of everything that happens in this universe. Allah’s Knowledge encompasses all of His actions and actions taken by His creation.
Allah, the Most Exalted, Says (what means): "And not absent from your Lord is any [part] of an atom’s weight within the earth or within the heaven or [anything] smaller than that or greater but that it is in a clear register." [Quran 10:61]
2. Pre-Recording: The belief that Allah recorded everything in a Tablet that He kept with Himself, called 'Al-Lawh Al-Mahfooth' (The Preserved Tablet). Allah, the Most Exalted, Says (what means): “Do you not know that Allah knows what is in the heaven and earth? Indeed that is in a Record [i.e., Al-Lawh Al-Mahfooth]. Indeed that, for Allah, is easy.” [Quran: 22:70]
Furthermore, Prophet Muhammad, sallallaahu ‘alaihi wa sallam, said: “The first thing which Allah created was the Pen. Then He ordered it to write. The Pen asked ‘What should I write?’ Allah said: ‘Write down everything that will occur until the Day of Judgment.’” [Abu Dawood]
'Abdullah Ibn 'Amr Ibn Al-'Aas said that he heard the Messenger of Allah say: “Allah recorded the measurement of all matters pertaining to creation fifty thousand years before He created the heavens and earth.” [Muslim]
3. The Will of Allah: The belief that nothing, whether related to Allah’s actions or actions taken by His creation, can occur without His permission. Almighty Allah Says (what means): “And your Lord creates what He wills and chooses...” [Quran: 28:68] And: “…And Allah does what He wills.” [Quran: 14:27] Allah also Says (what means): “It is He who forms you in the wombs however He wills…” [Quran: 3:6] As for actions taken by His creation, Allah Says (what means): “…And if Allah had willed, He could have given them power over you, and they would have fought you.” [Quran: 4:90] He also Says (what means): “…And if Allah had willed, they would not have done so. So leave them and that which they invent.” [Quran: 6:137]
4. Creation: The belief that Allah created all creation, all what they possess of attributes, and all their actions. Allah Says (what means): “Allah is the Creator of all things, and He is, over all things, Disposer of affairs.” [Quran: 39:62] He also Says (what means): “…He has created everything and determined it with [precise] determination.” [Quran: 25:2] Also, Allah informs us that Prophet Ibraheem (Abraham) said to his people (what means): “Do you worship that which you [yourselves] carve. While Allah created you and that which you do?” [Quran: 37:96]
Believing in Divine Decree and Predestination does not mean that people have no power over the actions they choose to take. Sharee’ah (the Islamic Law), as well as reality, confirm that man has a will of his own:
As for the Sharee’ah, Allah Says about one’s own will (what means): “…So he who wills may take to his Lord a [way of] return [by obeying his commandments].” [Quran: 78:39] He also Says (what means): “So come to your place of cultivation however you wish …” [Quran: 2:223]
As for one’s own power over his actions, Allah Says (what means): “So fear Allah as much as you are able and listen and obey…” [Quran: 64:16] He also Says (what means): “Allah does not charge a soul except [with that within] its capacity. It will have [the consequence of] what [good] it has gained, and it will bear [the consequence of] what [evil] it has earned…” [Quran: 2:286]
As for reality, every human knows that he has power and will of his own. He uses his power and will to indulge in or avoid actions of his choice. People distinguish between what they do by their own power and between what they have no power over, like shivering due to illness or extreme cold. However, the power and will of mankind is under the control of Allah’s Will and Power. Allah Says (what means): “…For whoever wills among you to take a right course. And you do not will except that Allah wills – Lord of the worlds.” [Quran: 81:28-29]. The universe is Allah’s property and nothing happens in His Kingdom without His Knowledge and Permission.