Praise be to Allah, and may peace and blessings be upon the Messenger of Allah. To proceed:
It is not permissible for a servant to use divine decree as an excuse for committing sins or abandoning obligatory duties; using divine decree in this way is invalid according to both Islamic law and reason. If such an excuse were valid, every person could commit whatever sins and acts of injustice he wished and then say: “This is the decree of Allah.”
The polytheists used divine decree as an argument to justify their polytheism, so Allah refuted them by saying:
﴿Those who associated others with Allah will say, “If Allah had willed, we would not have associated others with Him, nor would our fathers...”﴾ [Al-An'am: 148].
Allah, the Most High, also sent the messengers, revealed the Books, commanded His servants and prohibited things for them, and granted them ability, will, and choice. He said:
﴿Allah does not burden a soul beyond its capacity.﴾ [Al-Baqarah: 286].
A servant does not know what has been written for him before an action takes place. Rather, he knows his own choice and intention when he proceeds to perform an act of obedience or commit a sin. Therefore, it is not valid for him to use divine decree as an excuse for abandoning what Allah has commanded or doing what He has forbidden.
It is necessary to distinguish between what is willed for us and what is required from us. Whatever Allah has decreed for us that is beyond our choice is among what is willed for us. As for what He has commanded us to do and what He has forbidden us from doing, this is among what is required from us, and we are commanded to fulfill it.
It is permissible to invoke divine decree in the case of calamities that occur without the servant's choice, such as poverty, illness, the loss of a loved one, the destruction or loss of property, and similar events. In such cases, a Muslim may say: “Allah has decreed it, and whatever He wills, He does,” while remaining patient and content with Allah's decree.
As for sin, it is an action of the servant and occurs through his choice. Therefore, he may not use divine decree as an excuse for it. Rather, if he commits a sin, he must seek forgiveness, repent, feel remorse, and rectify whatever harm he has caused.
One of the clearest examples is a person who drives his car too fast and neglects safety precautions, thereby causing an accident. It is not valid for him to use divine decree as an excuse for his negligence, because he himself chose the means that led to it. However, if his car is damaged while it is parked, without any negligence on his part, he may say: “This is the decree of Allah.”
For this reason, the scholars said: “The fortunate person seeks forgiveness for his faults and is patient with his calamities.”
Some scholars have stated that if a person has repented from a sin and someone reproaches him for a sin from which he has already repented, it is permissible for him to invoke divine decree in the sense that the sin has become, in his case, a calamity that occurred and has ended, not in the sense of justifying the sin or removing responsibility for it. He has acknowledged his sin, repented, and sought forgiveness, and the one who repents from a sin is like one who has no sin.
This is illustrated by the story of the discussion between Adam and Moses, peace be upon them. Adam invoked divine decree regarding the calamity that resulted from the sin after it had occurred, not to justify the sin or to continue committing it.
The conclusion is: Divine decree must not be invoked as an excuse for sins or for abandoning obligatory duties. Rather, it may be invoked in the case of calamities over which the servant has no choice. A person who has repented from his sin should not be blamed for a sin from which he has repented. Belief in divine decree does not mean abandoning the means or removing responsibility. Rather, the believer combines action, obedience, and repentance with contentment with what Allah has decreed after it occurs.
And Allah, the Most High, knows best.