There are several āyāt in the Qurʾān that mention everlasting punishment in the Fire as a recompense for the perpetration of misdeeds and major sins which are not themselves disbelief. For example, the statements of the Most High:

وَمَن يَقْتُلْ مُؤْمِنًا مُّتَعَمِّدًا فَجَزَاؤُهُ جَهَنَّمُ خَالِدًا فِيهَا وَغَضِبَ اللَّهُ عَلَيْهِ وَلَعَنَهُ وَأَعَدَّ لَهُ عَذَابًا عَظِيمًا

“And whoever kills a believer intentionally, his recompense is Hell to abide therein, and the wrath and the curse of Allāh are upon him, and a great punishment is prepared for him.”
(Al-Nisāʾ, 4:93)

وَمَن يَعْصِ اللَّهَ وَرَسُولَهُ وَيَتَعَدَّ حُدُودَهُ يُدْخِلْهُ نَارًا خَالِدًا فِيهَا وَلَهُ عَذَابٌ مُّهِينٌ

“And whosoever disobeys Allāh and His Messenger (Muḥammad (صلى الله عليه وسلم)), and transgresses His limits, He will cast him into the Fire, to abide therein; and he shall have a disgraceful torment.”
(Al-Nisāʾ, 4:14)

بَلَىٰ مَن كَسَبَ سَيِّئَةً وَأَحَاطَتْ بِهِ خَطِيئَتُهُ فَأُولَٰئِكَ أَصْحَابُ النَّارِ ۖ هُمْ فِيهَا خَالِدُونَ

“Yes! Whosoever earns evil and his sin has surrounded him, they are dwellers of the Fire (i.e. Hell); they will dwell therein forever.”
(Al-Baqarah, 2:81)

So how should these āyāt be commensurated with other authentic evidences from the Book of Allāh and the Sunnah of His Messenger (صلى الله عليه وسلم) which prove that only the disbelievers shall experience everlasting punishment in the Fire, and that the believers—regardless of the sins they have perpetrated during their lifetime—shall without a doubt eventually be extricated from it?

Firstly, concerning the interpretation of these āyāt, there is no difference among the pious predecessors. These āyāt have been interpreted by them in a manner that is consistent with the foundation [of Ahl al-Sunnah that all believers who perpetrate major sin shall enter Paradise eventually, even if subjected to punishment in Hell for a period of time before that entry]. In consideration of this foundation, the most exemplary explanation ever made in this regard is that mention of everlasting punishment as a recompense for any sin besides disbelief or shirk is meant to indicate that the sin being referred to is so serious that it would have led to everlasting punishment because of its horrid, despicable nature. That is, everlasting punishment for its perpetrator would have occurred had that which prevented such punishment (īmān) not also been present. As īmān prevents everlasting punishment in Hell is a widely recognised foundation of Islām. Thus, these passages are interpreted in a manner that is consistent with this well-known foundation. In general, religious rulings are only instated once the prerequisites for that ruling have been fulfilled (here, īmān being a prerequisite for entry into Paradise and removal from the Fire), and its preventers non-existent (here, outright disbelief or shirk). This is a matter that is plainly evident—and all praise and thanks belongs to Allāh.

Note also that, in some of the āyāt mentioned, the sin being referred to is indeed outright disbelief. This includes the āyah in which Allāh says: “and his sin has surrounded him” which indicates disbelief because disobedient acts that are less severe than disbelief are not described as “surrounding” the perpetrator. This is because the co-existence of īmān within the perpetrator shall prevent such surrounding.

This is also the case with the āyāh: “And whosoever disobeys Allāh and His Messenger (Muḥammad (صلى الله عليه وسلم)), and transgresses His limits, He will cast him into the Fire, to abide therein; and he shall have a disgraceful torment.” Here, the term ‘disobedience’ encompasses outright disbelief, major and minor sin. If the āyah is interpreted as referring to outright disbelief, the entire premise of the question posed becomes non-existent, the problem in the interpretation of such āyāt alleviated.

Source: Fawāʾid Qurʾāniyyah: 66-68
Translated by: Riyāḍ al-Kanadī