The sixth and final article of Islamic belief, as detailed by a famous prophetic Tradition is belief in destiny, its good and evil. The Arabic word for destiny, qadar, implies the measuring out of something or fixing a limit to it. Thus, in a technical sense, destiny is the divine decree in its fixing limits for existent things, or its measuring out the being of things. Early Muslims would simply define destiny as knowledge that what hits you was not going to miss you, and that what misses you was not going to hit you.
In our discussion of qadar it should be noted that a true and full understanding of the subject is reserved for the select few who have sacrificed great amounts of time and energy for the sake of Islam, after which Allah expands their understanding of complex concepts like this that cannot be contained in logical formulas alone. The Prophet Muhammad (peace and blessings be upon him) is reported to have said, “Whenever Allah desires good for His bondsman, He gives him deep understanding of the religion and He inspires him with righteous guidance” (reported by Tabarani).
There are many degrees and depths in understanding the concept of qadar. Given that different people demand different approaches in explaining unfamiliar concepts, we shall attempt to explain a few dimensions, including both the requisite (wajib) tenets and some of the esoteric.
Sheikh Muhammad al-Jurdani defines belief in destiny as the conviction “that Allah Most High has ordained both good and evil before creating creation, and that all that has been and all that will be only exists through Allah’s decree, preordainment, and will.” 
At the same time, our apparent choice and will in matters is not mere illusion. As such, a person may feel guilty when he performs a wrong or evil action, but he does not feel answerable to others when a medical affliction, for instance, strikes him. Maulana Ashraf Ali Thanwi explains, “The existence of man’s authority or option is a self-evident truth, but simultaneously it is also clear that this attribute of his authority is created (makhluq) and every chain of creation reaches back to its Creator. The authority of man will be nonexistent in some matters, thereby proving his ultimate powerlessness and helplessness. Thus, a man is neither completely helpless nor is he completely free in power and authority.”
“Allah has willed that you act based on choice.”
Allah’s knowledge eternally encompasses all things necessary, possible, and impossible. The crux of the purpose of existence is our full and experiential realization that Allah is eternally and absolutely knowing of everything and that His Power is singularly orchestrating every event and thing, for Allah says in the Qur’an:
[Allah is He Who created seven heavens, and of the earth the like of them; the decree continues to descend among them, that you may know that Allah has power over all things and that Allah indeed encompasses all things in (His) knowledge.] (Talaq 65:12)
Because His Knowledge, Will, and Power are absolute and unbounded, Allah knows the results of all events and choices before their occurrence. A human being, however, does not have access to this knowledge, and thus he acts in accordance with a desire from within him. Even though his ultimate choice corresponds with Allah’s eternal knowledge, he is still accountable for it.
As some Islamic theologians have explained it, “Allah has willed that you act based on choice.” We are held responsible for choosing an act but not for creating the act itself. In other words, Allah creates the act and by our choosing it, we “acquire” it and are thereby held responsible for it. Thus, human actions are created by Allah but performed by us.
The proofs for this subtle relationship are many. For instance, an insane person, a child, and a sleeping person are not held accountable for their actions according to Sacred Law both in this world and the next. If a man sincerely forgets to pray or fast when it is obligatory upon him, he is not considered sinful. Similarly, the king Nimrod tried to burn the Prophet Ibrahim (Abraham, peace be upon him), as is detailed in a famous Qur’anic account, though Allah willed that the fire not burn His beloved Prophet. Nevertheless, even though he failed to execute his evil designs, Nimrod sinned for choosing to harm Ibrahim and is therefore doomed in the next world.
A famous Islamic maxim states, “The foremost energies cannot pierce the walls of foreordained destinies.” Whether we are removed from worldly causes and effects or are deeply submerged in them, we must always maintain the firm conviction that Allah’s Will, Power, and Preordainment control all affairs. In reality, Allah is the Doer of everything, such that causes in themselves do not carry independent efficacy. To believe that medicine in itself cures disease, for instance, is essentially to posit that a created thing is acting independent of its Creator. In other words, the thing would then be beyond the control of Allah, a belief that is little better than attributing a partner to Him. Yes, Allah ties things together according to a recurrent way, such that He satisfies hunger when a person eats, yet controlling it all is His singular Will and Power.
We do not stop eating, however, because we believe that the food itself is not satisfying our hunger. For one thing, Allah orders us in the Qur’an to eat and drink of wholesome food. But even with things that are not explicitly mentioned in the Qur’an, we must maintain proper conduct with the reoccurring system of order that Allah has put at our disposal. While Allah may change His recurrent way of tying things together (in the form of miracles) for those who are close to Him, it would be little more than rebellion against Him and His system for a common person to completely disregard the world in front of him.
The Prophet Muhammad (peace and blessings be upon him) has explained some of the practical implications of this belief in his saying, “If something befalls you, don’t say: If only I would have done such and such, rather say: Allah foreordained this, and whatever He wishes, He does; for verily the phrase ‘if only I would have’ makes way for the work of Satan” (reported by Muslim).
In a similar vein, contemporary psychology has discovered innumerable psychological ailments connected with one’s dwelling on past events and past mistakes or lost opportunities. We must constantly remind ourselves that yesterday has passed and will never come back, and tomorrow is merely a possibility. The only real currency we have to work with is “now.” For this reason, one of Satan’s most effective traps is procrastination. Many people have vowed to return to Allah and reform their ways at some future juncture, but they left this world before they were given the opportunity.
The Prophet Muhammad (peace and blessings be upon him) asked one of his Companions, “Shall I not guide you to words that are a treasure from the treasures of Paradise?” He said, “Of course, O Messenger of Allah!” The Prophet (peace and blessings be upon him) said, “There is no ability or power except through Allah” (reported by Bukhari and Muslim). The reality of these words is the crux of a full and proper understanding of qadar.
By Noor al-Deen