Is eternity in Paradise different from eternity in Hellfire, and does disbelief in this world necessitate eternal torment, while acknowledging that Allah is the Most Just of all judges?

Eternal immortality is not exclusive to the people of Paradise; it is also mentioned for the people of Hell in the Quran, as in His Almighty saying: "except the path to Hell, wherein they will abide forever," and "abiding therein forever, they will not find any protector or helper." The eternity of the disbeliever in Hell is justice and wisdom, because disbelief is a great injustice that indicates an evil disposition, and "if they were sent back, they would return to that which they were forbidden." As for those who will not abide eternally in Hell, they are those whose sin did not reach the level of disbelief or associating partners with Allah, for Allah "does not forgive that partners be associated with Him, but He forgives anything less than that for whomever He wills." Allah possesses ultimate wisdom in His creation; there is no repeller of His decree.