A Muslim must believe in the existence of a place of enjoyment (Paradise) and also a place of punishment (Hell) in the hereafter.
We should believe this life is a temporary place of stay and we'll account for all we did in it.
The People of Hell are categorised in to two: The first group (A) are temporary hell dwellers while the second group (B) are permanent dwellers.
The first group are Muslims who affirmed the oneness of Allah (Tawheed) but were guilty of some sins for which they had to be punished in Hell. After some time as Allah wills, they will enter Paradise.
It was narrated from Abu Sa’eed al-Khudri that the Messenger of Allaah (peace and blessings of Allaah be upon him) said: “Allaah will say: ‘The angels have interceded, the Prophets have interceded and there is no one left but the Most Merciful of those who show mercy.’ Then He will take a handful from Hell, and will bring out people who never did any good and who will have turned into