The Quran and prophetic tradition delineate fusuq and ẓulm with precision, highlighting their broad implications. Fusuq is derived from a root meaning "to go outside" or "to stray beyond a limit," and in Islamic terminology, it signifies "going beyond the circle of obedience to Allah, or transgressing the commandments of Allah." As Ma'arif-ul-Quran explains, this transgression can range from habitual sin to outright denial (kufr). The word fasiq (one who commits fusuq) can thus apply to a disbeliever or a habitual Muslim sinner, with public unashamed sinning sometimes equating to kufr in the jurists' view.

Ẓulm, often translated as injustice or wrongdoing, has an even broader scope. It encompasses putting things in improper places, indicating a deviation from divine order. Idol worship, for instance, is identified as a form of ẓulm because it wrongly attributes divine attributes to created beings “when you took for worship the calf after him, while you were wrongdoers”. Ibn Kathir identifies three types of injustice (ẓulm): the unforgivable sin of shirk (associating partners with Allah), failing to fulfill Allah's rights (Huququllah), and violating the rights of others (Huquq al-‘Ibad). The Quran states that those who disbelieve and act unjustly will not be forgiven, nor will they be guided to a way of good, except the way of Hell, to dwell therein forever.

The inherent weakness of humanity is acknowledged, as man was created weak. This weakness makes humanity susceptible to desires that can lead to fusuq and ẓulm. As Tafsir al-Jalalayn notes, this weakness particularly relates to "abstaining from women and passions." Yet, Allah desires to lighten things for you, prescribing injunctions that are within human capacity.

The Quran provides numerous historical accounts to illustrate the consequences of fusuq and ẓulm. The Children of Israel serve as a prominent example, their history marked by repeated lapses in obedience. After witnessing the miracle of their escape from Pharaoh, they immediately 2:54. Their repentance, as prescribed by Allah, involved the innocent slaying the guilty among them, demonstrating the severity of this ẓulm.

Their disobedience continued when they “changed words to a statement other than that which had been said to them”, opting for mockery instead of sincere supplication for forgiveness. This led to a divine punishment of plague, as Ma'arif-ul-Quran explains, highlighting the grave sin of altering divine commands. Another instance of transgression involved their “disobedience concerning the sabbath”, where they sought deceitful means to circumvent the prohibition of fishing on Saturday. This persistent fusuq resulted in their transformation into "apes, despised", a physical metamorphosis rather than merely a psychological one, according to Ma'arif-ul-Quran, serving as a deterrent and a lesson for all.

Furthermore, the Children of Israel’s repeated rejection and killing of prophets, such as Zachariah and John, and their disbelief in the signs of Allah, are cited as reasons for their humiliation and misery. They were admonished for 2:85 despite being bound by a covenant not to do so. This selective belief in scripture and their cooperation in "sin and aggression" demonstrate a deep-seated fusuq and ẓulm.

The concept of hypocrisy (nifaq) is closely related to disobedience and transgression. Hypocrites outwardly claim faith but harbor disbelief and ill intentions in their hearts. They are described as those in whose hearts is a sickness, a doubt and hypocrisy that Allah increases. Ibn Kathir explains this as a disease in religion, not physical ailment, which causes them to increase in shameful behavior.

Hypocrites engage in mischief on earth by disobeying Allah and His Messenger, continuing prohibited acts, and doubting Allah's religion (Tafsir Ibn Kathir). They claim to be "only peacemakers" while actively working against the believers, even conspiring with disbelievers. The Quran warns that they are the ones who make mischief, but they perceive not. This deception extends to their interactions, where they say, "We believe," when with believers, but when alone with their leaders ("Shayatin"), they confess, "We are with you; we were only mocking." Allah mocks them in return and leaves them to wander blindly in their deviation.

The Quran uses parables to illustrate the state of hypocrites. Some are likened to a person who kindles a fire for light but then loses it and is left in darkness, symbolizing those whose disbelief is deeply rooted. Others are compared to those caught in a rainstorm, walking in flashes of lightning but stopping in darkness, representing their hesitation and doubt. Ibn Kathir clarifies that these parables describe different types of hypocrites, from pure hypocrites to those with some hypocrisy in them, a condition also described in a Hadith: "Whoever has the following three (characteristics) will be a pure hypocrite, and whoever has one of the following three characteristics will have one characteristic of hypocrisy, unless and until he gives it up: Whenever he speaks, he tells a lie. Whenever he makes a covenant, he proves treacherous. Whenever he is entrusted, he breaches the trust" (Bukhari, Muslim).

Islamic jurisprudence (Fiqh) addresses fusuq and ẓulm by establishing clear guidelines for obedience and justice, and outlining the severe consequences of violating these principles. The Quran explicitly prohibits taking the property of others unjustly, saying, eat not up your property among yourselves unjustly. This injunction encompasses all impermissible means of acquiring wealth, such as Riba (interest), gambling, theft, and bribery. As Ma'arif-ul-Quran notes, any unauthorized use of another's property, even if not eaten, is considered "eating up" it unjustly.

The prohibition against killing is also paramount. Do not kill yourselves includes both suicide and unjust murder of others. The Quran reserves severe punishment for intentional murder, stating, whoever kills a believer intentionally, his recompense is Hell. While there is scholarly debate on whether a murderer's repentance is accepted, the majority of scholars believe it can be, provided it is sincere and followed by righteous deeds, although the punishment for the crime remains. Ibn Abbas, however, held that the intentional murderer's repentance would not be accepted, and this verse was the last revealed on this subject, not abrogated.

The Shariah also outlines punishments for specific transgressions. For instance, early Islamic law prescribed confinement for women who committed illegal sexual intercourse, later abrogated by flogging or stoning (4:15, 4:16). Homosexuality is strictly forbidden, with severe warnings from the Prophet Muhammad ﷺ, who said, "If you find someone doing what the people of Lot did, kill both the doer and the one with whom it is done" (At-Targhib wat-Tarhib). Jurists have proposed various severe punishments, including burning, stoning, and beheading, for this act.

Justice is commanded even towards enemies: let not the enmity and hatred of others make you avoid justice. This emphasizes that justice is a divine obligation, transcending personal biases. Furthermore, enjoining good and forbidding evil is a collective responsibility, and those scholars who fail to do so are criticized: Why do not the Rabbaniyyun and the Ahbar forbid them from uttering sinful words and from eating illegal things? Evil indeed is that which they have been performing.

The spiritual consequences of fusuq and ẓulm are dire, leading to divine wrath and eternal punishment. Those who disobey Allah and His Messenger and transgress His limits 4:14. Disbelievers who persist in their denial are described as "fuel for the Fire", their wealth and children being of no avail against Allah's punishment.

The Quran emphasizes that the true value of worldly life is fleeting compared to the Hereafter. Desirable things like women, children, wealth, and land are merely an enjoyment of the worldly life, while with Allah is the beauty of the final resort. Engaging in fusuq and ẓulm often stems from an excessive love for these worldly attractions, leading individuals to "purchase error with guidance", thereby suffering a profitless trade.

Despite the gravity of these sins, Allah's mercy remains open. For those who believe and perform righteous deeds, there is forgiveness and a great reward. Repentance is a fundamental avenue for forgiveness. Even those who commit evil or wrong themselves, if they seek Allah's forgiveness, he will find Allah Oft-Forgiving, Most Merciful. This promise applies to all sins short of shirk, which Allah does not forgive except that (anything else) to whom He wills. Sincere repentance, coupled with righteous deeds, is the path to divine acceptance and entry into Paradise. As a Hadith states, "Whoever has the least speck of faith in his heart shall ultimately depart the Fire" (Bukhari, Muslim).

In conclusion, fusuq and ẓulm represent a profound spiritual divergence from divine norms, encompassing acts of disobedience, injustice, and denial. The Quranic narratives and prophetic traditions consistently warn against these transgressions, illustrating their severe consequences in this life and the Hereafter. Yet, central to the Islamic message is the ever-present path of repentance, highlighting Allah's infinite mercy for those who sincerely strive for righteousness, offering a transformative journey from deviation to divine favor.