I read in the book "Al-Fiqh Al-Akbar" by Imam Abu Hanifa (may Allah have mercy on him), where he states that whoever believes that the Hellfire will cease to exist – meaning that the punishment of the disbelievers is not eternal – is committing disbelief (Kufr). I have also read similar statements in the works of many scholars from the Shafi'i, Hanafi, Maliki, and other schools of thought. Some scholars even authored books specifically to clarify that the Hellfire and its punishment for disbelievers are eternal, which is clearly supported by numerous Quranic verses and authentic Hadiths. From my understanding, this is the consensus (ijma') of the scholars of the Ummah. However, a few days ago, I read a book by a contemporary author who claims that the Hellfire will cease to exist and that the punishment of disbelievers is not eternal. He also mentioned that there is an opinion that the disbelievers in Hellfire will eventually enter Paradise. I was very surprised by this, and my question is: Is it permissible for a Muslim to believe that Hell is not eternal and that it will cease to exist? Is this belief considered Kufr, or is it simply misguidance (Dalal) but not disbelief? Or is this a minor issue that does not have a significant impact, despite the many clear verses and authentic Hadiths on the subject? Please guide us to the truth, and may Allah bless you.