﴿ لِّيَجْزِىَ ٱلَّذِينَ ءَامَنُوا۟ وَعَمِلُوا۟ ٱلصَّٰلِحَٰتِ ۚ أُو۟لَٰٓئِكَ لَهُم مَّغْفِرَةٌۭ وَرِزْقٌۭ كَرِيمٌۭ ﴾

“to the end that He may reward those who believe and do right­eous deeds: [for] it is they whom forgiveness of sins awaits, and a most excellent sustenance”

The addressees of the Quran were not disbelievers in the Day of Judgement. It was just that they did not believe that Judgement Day would bring them humiliation and punishment. The world they lived in appeared safe to them and they could not, therefore, understand how they would be in jeopardy on reaching the world Hereafter. This truth about life and the Universe is found in all divine scriptures. It is the Quran’s mission to reveal this reality in its pure and unadulterated form. Now, those who take a stand in opposition to this mission are indulging in the most improper bravado. Before God, they will be treated as deserving of the severest punishment.