Answered by Shaykh Yusuf Weltch
Are there any muslim sinners that abide in hell forever?
In the Name of Allah, the Most Merciful and Compassionate
On the Day of Judgment the Muslims will be taken to account for their deeds in this world. Thereafter, they will either be granted the Mercy of Allah Most High and directly be entered into Paradise. Others who are not granted this mercy will be punished in Hellfire for an appointed time corresponding to their sin.
Despite some of the Muslims entering Hellfire, all will eventually be removed at some point, either through intercession or because they remained the entire length decreed by Allah Most High.
The Messenger of Allah (may Allah bless him and give him peace) said, “I know the last of the inhabitants of Hellfire to exit and the last of the inhabitants of Paradise to enter. He is a man who will come crawling out of Hellfire and Allah will say, ‘Go and enter Paradise! You have the like of the entire world plus ten times that.’ The man will reply, “Do you mock me while You are King?” He (The narrator) said, “I then saw the Messenger of Allah (may Allah bless him and give him peace) smile such that his molars showed.” He (the Messenger) would say, “That is the least abode of Paradise.” [Bukhari and Muslim]
Residing Forever in Hellfire
The only sin that would cause one to remain in Hellfire for eternity is disbelief in all its types. Allah Most High says, “Indeed, Allah does not forgive associating others with Him ˹in worship˺, but forgives anything else of whoever He wills. And whoever associates others with Allah has indeed committed a grave sin.” [Quran, 4:48]
Note that the scholars are unanimous that ‘associating others with Allah (shirk)’ includes disbelief in Islam, even if done in a manner of monotheism. [Razi, Mafatih al-Ghaib]
Hope this helps
Allah knows best
[Shaykh] Yusuf Weltch
Checked and Approved by Shaykh Faraz Rabbani