Persisting in Sin

Praise be to Allah, and peace and blessings be upon the Messenger of Allah.

According to Ahl al-Sunnah wa al-Jama'ah, istihlal (declaring something lawful that Allah has forbidden) means believing that something prohibited by Allah is actually lawful—for example, believing that adultery, alcohol, or usury are permissible, while knowing that Allah and His Messenger have forbidden them. Such a belief constitutes disbelief (kufr) if it concerns a matter that is necessarily known to be forbidden in Islam and the person has no valid excuse, such as ignorance or a mistaken interpretation.

However, merely committing a sin, persisting in it, or repeating it does not mean that a person considers it lawful, as long as they still believe that it is forbidden and acknowledge Allah's ruling concerning it, even if they are overcome by their desires or weakened by their faith. Therefore, a person who drinks alcohol, commits adultery, or deals in usury while saying, "I know it is forbidden, but I was overcome by my desires," is a sinful Muslim who has committed a major sin, not a disbeliever merely because of committing that sin.

Likewise, loving a sin is not always the same. If a person is drawn to a sin because of natural desire while still believing that it is forbidden, this reflects weakness in faith but does not take them out of Islam. Nevertheless, they are obligated to struggle against their desires and repent to Allah. However, if a person's love for the sin stems from hatred of Allah's ruling, rejection of His prohibition, or dissatisfaction with His law, then this contradicts faith itself, because a true believer accepts Allah's judgment even when it conflicts with personal desires.

For this reason, the scholars distinguished between a person who sins while remaining submissive to Allah's ruling and one who rejects Allah's ruling or arrogantly refuses to accept it. The first is a sinful believer whose faith is deficient, whereas the second may fall into disbelief if all the conditions for declaring disbelief are fulfilled and no valid impediments exist.

Even so, persisting in sins is extremely dangerous because it weakens and hardens the heart. If a person does not repent, it may eventually lead them away from the truth. For this reason, some of the early Muslim scholars said:

"Sins are the pathway to disbelief."

This means that sins may become a road leading to disbelief, even though they are not disbelief in themselves.

In summary: Istihlal means believing that what Allah has forbidden is actually lawful—it is not merely committing the forbidden act. Whoever persists in a sin while believing it to be forbidden remains a sinful Muslim and does not become a disbeliever for that reason alone. However, whoever denies that it is forbidden, hates Allah's ruling regarding it, or refuses to submit to His judgment has fallen into the type of istihlal that may take a person out of Islam after the necessary conditions for declaring disbelief are fulfilled and any valid impediments are absent.

And Allah knows best.