6. Belief in Al-Qadar (Divine preordainment):

It is to have a firm belief that everything that happens in this universe whether it is good or evil happens by the will, decree and preordainment of Allaah and that He The Exalted is the Effecter of what He intends. Nothing can occur except what He wants. Nothing can go out of His will. Nothing in the whole universe can do something against His decree nor can occure except through His arrangements. No one can escape the preordained decree nor can go beyond what is written in Al-Lawh Al-Mahfooth (The Preserved Tablet). He is the One Who created the actions, obedience and disobedience of the slaves. In spite of this fact, He The Almighty ordered and forbade them. He gave them free choice in their actions and did not compel them to do such actions; rather, they occur according to their abilities and wills. Allaah The Almighty created them and their abilities. He The Exalted guides whomever He wills with His mercy and misguides whomever He wills with His wisdom. He The Exalted is not questioned about what He does, but they will be questioned. 

It is of four degrees:

Firstly:Belief in the eternal knowledge of Allaah that encompasses all things, and that He The Almighty knew what happened, what is going to happen and what did not happen, how it would have been if it had happened. Allaah The Almighty says: {So you may know that Allaah is over all things competent and that Allaah has encompassed all things in knowledge.} [At-Talaaq: 12]

He The Almighty also says: {He is Allaah, other than whom there is no deity, Knower of the unseen and the witnessed.} [Al-Hashr: 22]

He The Almighty also says: {And with Him are the keys of the unseen; none knows them except Him. And He knows what is on the land and in the sea. Not a leaf falls but that He knows it. And no grain is there within the darknesses of the earth and no moist or dry [thing] but that it is [written] in a clear record.} [Al-An‘aam: 59]

Secondly:Belief that Allaah The Almighty wrote everything that is going to happen until the Hour starts. Allaah The Almighty says: {Do you not know that Allaah knows what is in the heaven and earth? Indeed, that is in a Record. Indeed that, for Allaah, is easy.} [Al-Hajj: 70] He The Almighty also says: {And all things We have enumerated in a clear register.} [Yaa-Seen: 12]

Thirdly:Belief that the will of Allaah is irresistible and nothing can escape His might. Allaah The Almighty have willed whatever therein the heavens and the earth. Nothing can happen except what He The Exalted wills. So whatever Allaah The Almighty will come to pass and whatever He does not will, will never occur. Allaah The Almighty says: {And Allaah does what He wills.} [Ibraaheem: 27]

He The Almighty also says: {And you do not will except that Allaah wills - Lord of the worlds.} [At-Takweer: 29]

Fourthly: Belief that Allaah The Almighty created and originated all things. He The Exalted is the Creator alone without any partner. He is the creator of every worker and his work, every moving creature and its movements and every motionless being and its stillness, Allaah The Almighty says: {And has created each thing and determined it with [precise] determination.} [Al-Furqaan: 2]

He The Almighty says: {Allaah is the Creator of all things, and He is, over all things, Disposer of affairs.} [Az-Zumar: 62]

He The Almighty says: {While Allaah created you and that which you do?"} [As-Saafaat: 96]

Belief in Al-Qadr does not contradict with the idea that the slave has a will and ability in his optional actions. They are thebasis of the obligations on which reward and punishment based. Allaah The Almighty says: {So he who wills may take to his Lord a [way of] return.} [An-Naba’: 39]

He The Almighty says: {For whoever wills among you to take a right course.} [At-Takweer: 28]

He The Almighty says: {Allaah 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.} [Al-Baqarah 286]

Every individual knows that he has a will and ability with which he can do or leave something. He can easily differentiate between his will in any action such as walking or what occurs away from his will such as trembling. However, the will and the ability of the slave only occur by the will and ability of Allaah The Almighty. Allaah The Almighty says: {And you do not will except that Allaah wills.} [Al-Insaan: 30]  

And because the whole universe is owned by Allaah The Almighty, then nothing can occur in His kingdom away from His knowledge and will.