How can it be right for the perpetrators of grave sins and those who affirmed God's Oneness to enter Paradise with the righteous servants of God, after their torment in the Fire, despite their enjoyment of disobedience in this world?

This matter should not occupy your thoughts, for Allah Almighty is the Most Merciful of those who show mercy, and the Most Just of those who judge justly. All His decrees are goodness, mercy, wisdom, and justice. Submission to what Allah has informed us is obligatory, and there is no injustice to the diligent in the entry of disobedient people into Paradise. Indeed, the inhabitants of Paradise are in degrees, as Allah Almighty said: "Look how We have preferred some of them over others. But the Hereafter is greater in degrees [of difference] and greater in preference." (Al-Isra: 21). The rank of the Prophets is not like the rank of common people. So, whoever obeys Allah until he reaches the status of the devoted (al-Muqarrabun) is in a higher class than those below him. Disobedient monotheists are tormented in the Fire according to their sins, and when they are purified, they will exit it. The Fire's heat is intense and its torment is painful; a single dip in it removes all joy. Therefore, a Muslim must submit to Allah's judgment and rejoice in what Allah has bestowed upon this Ummah by making all monotheists enter Paradise.