Allah has given two positions to every descendent of Aadam: a position in Jannah and a position in Jahanam. Then whoever is destined to damnation of the kuffaar and mushrikeen will inherit the positions in Hell that had been allocated to the people of Paradise, and those of the people of Paradise for whom eternal bliss is decreed will inherit the portions of Paradise that had been allocated to the people of Hell. After describing the good deeds that would earn Paradise for the successful believers, Allah said, “These are indeed the inheritors, who shall inherit the Fridays”
Ibn Katheer said in his commentary on this aayah: “Ibn Abi Haatim said – and he quoted to the isnaad going back to Abu Hurayrah (ra) that the Messenger of Allah (saw) said:
“There is no one among you who does not have two positions, one in Paradise and one in Hell. The believer will have a house built for him in Paradise, and his house in Hell will be demolished”. A similar report was narrated from Sa’eed ibn Jubayr.
The believers will inherit the positions of the kuffaar, because those positions were created for those who worship Allah (swt) alone and do not associate anything in worship with Him, because they did what they were commanded to do as far as worship is concerned, whilst the kuffaar neglected the duty for which they had been created. So the believers gained the share that the kuffaar would have gained if they had obeyed Allah (swt) and they will gain even more than that. Muslim reported from Abu Burdah from Abu Musaa that the Prophet (saw) said: “Some people amongst the Muslims will come on the Day of Resurrection with sins as great as a mountain. Allah will forgive them, and will pass [the burden of sin] to the Jews and Christians”. According to another version of this hadith, the Prophet (saw) said, “When the Day of Judgement comes, Allah (swt) will allocate a Jew or Christian for every Muslim and will say, “This is your ransom from the Fire”. This hadith reflects the words of Allah (swt):
“Such is the Paradise which We shall give as an inheritance to those of Our slaves who have been al-Muttaqoon” [19:63] and
“This is the Paradise which you have been made to inherit because of your deeds which you used to do [in the life of this world]” [43:72] [Tafseer Ibn Katheer, 5/10]