This topic has drawn much debate for centuries between Muslim theologians as well as with non Muslims.
Some consider it a very complex issue and some find it very simple to explain.
With the hope of presenting a simpler version of the answer, we start with definition of Destiny/Qadar:
The word “qadar” in Arabic is translated into destiny/fate in English. It also means “divine fore-ordainment or predestination.”
Believing in Qadar/Destiny is also one of the six articles of faith (belief in the Oneness of Allah, Revealed books, the Prophets, Day of Resurrection the Angels, and destiny.)
To demonstrate the very first example of freewill, we will revisit the story of the creation of angels, Jinn, and Adam.
Allah has revealed in the Quran that He created angels from light, the Jinn from fire and the first human, namely Adam, from dust. He bestowed freewill to the Jinn and humans but not to the angels. Humans were the last of the three creations.
After the creation of Adam, Allah ordered the angels to prostrate to him, they all did, as they were created only to obey. But Satan refused as he considered himself loftier than Adam. First example of Freewill!
Could God destroy him?
He had given him freewill and Satan made his choice on this matter.
Was Satan an Angel?
In contrast to the Christian belief that Satan/Lucifer was one of the angels, Islam clearly refutes this idea by clarifying that had he been an angel, he would never have disobeyed. This is confirmed by further mention in the Quran that he was made from smokeless fire and he was indeed from the Jinn species.
In the story we learn that as Satan was cast out of Paradise due to his disobedience, later he also caused Adam and Eve to disobey Allah and thus be cast out as well.Second example of freewill!
Could God stop them from obeying Satan?
He would not compel anyone, while they have freewill.
The Angels prostrated themselves all of them together. Except Satan, he refused to be among the prostrators. God said: ‘O Satan! What is your reason for not being among the prostrators? ‘Satan said: ‘I am not the one to prostrate myself to a human being, whom You created from sounding clay of altered black smooth mud.’ God said: ‘Then get out from here for verily you are an outcast or cursed one. Verily the curse shall be upon you till the Day of Resurrection.’ (Quran 15:30-35)
As Satan and his host started their mischief on earth, Allah sent clear warning to humankind regarding Satan’s fall and his plot to misguide them.
And [mention] when We said to the angels, “Prostrate to Adam,” and they prostrated, except for Iblees/Satan. He was of the jinn and departed from the command of his Lord. Then will you take him and his descendants as allies other than Me while they are enemies to you? Wretched it is for the wrongdoers as an exchange. (18:50)
Some may say, “Is it fair to leave Satan to run loose and cause havoc among humans to commit disobedience against God and then send humans to Hell for this?” Allah, the Merciful, answers this when he mentions human’s choice after creation:
Verily, We showed him (human) the way, whether he be grateful or ungrateful. (76:3)
He guided humans through sending succession of Prophets in order to guide mankind, while Satan was busy at work to turn people away from God.
As for the issue of fate or destiny, Muslims believe that all that would happen in a person’s life is already written before his/her birth. So, some argue that if one is destined to Hell, or Heaven, then where is the freewill in this?
The answer is simple. The fact that it is written, does not mean we are aware of it. It only means that Allah is aware of what we will do, but is not compelling us to do it.
Among Muslims there are those who believe we do not have a choice or freewill, called the Jabrians (from jabr = compulsion). They deny all free agency in man and say that man is necessarily constrained by the force of Allah’s eternal and immutable decree to act as he does.
Yet, Allah mentions numerous times in the Quran that faith and works are essential components of paving one’s way to Paradise. This is only possible with freewill.
But those who believe and do deeds of righteousness, We shall admit them to Gardens under which rivers flow (i.e. in Paradise) to dwell therein forever. Allah’s promise is the Truth; and whose words can be truer than those of Allah? (4:122)
He also says:
Allah has promised those who believe and do deeds of righteousness that for them there is forgiveness and a great reward (i.e. Paradise). (5:9)
From numerous verses like the above, it is quite clear that we have a choice to do good or evil and are judged accordingly. However a good doer without faith will receive reward and what he asks for in this world but not portion of the good of the Hereafter.
Whoever desires the harvest of the Hereafter – We increase for him in his harvest. And whoever desires the harvest of this world – We give him thereof, but there is not for him in the Hereafter any share. (42:20)
Looking at the distant past, we find those who also claimed having no choice in the matter and worshipped other than Allah, claiming that if Allah wanted, they would not have done so.
And they said:
“If it had been the Will of the Most Gracious (Allah), we should not have worshipped them (false deities).” They have no knowledge whatsoever of that. They do nothing but lie! (43:20)
Yet, when clear proof was presented to them and they had no other direction to run to, they said:
We found our fathers following a certain way and religion, and we guide ourselves by their footsteps. (43:22)
(The messenger) said: “Even if I bring you better guidance than that which you found your fathers following?” They said: “Verily, We disbelieve in that with which you have been sent.” (43:24)
The above verses make clear personal choice in all matters has been the norm from Creation to this day.
There are also those who believe humans have all the choice and Allah is not aware of what they will do until they do it. Yet Allah says:
…And He knows whatever there is in the land and in the sea; not a leaf falls, but He knows it. There is not a grain in the darkness of the earth, nor anything fresh or dry, but is written in a Clear Record. (6:59)
It is clear that we are given guidance as well as freedom to choose. Totally up to us! We reap the consequences according to our choices. The fact that our choices and fate is written prior to birth only indicates that the Almighty Wise Creator is the Knower of all things.
Blaming people’s misguidance on anything other than personal choice may indicate some injustice from Allah. A better understanding of Allah’s word clarifies all misunderstandings.
..And your Lord is not unjust to anyone… (18:49)