الَّذِينَ اتَّخَذُواْ دِينَهُمْ لَهْوًا وَلَعِبًا وَغَرَّتْهُمُ الْحَيَاةُ الدُّنْيَا...

7:51. "Such as took their religion to be mere amusement and play, and were deceived by the life of the world."

...فَالْيَوْمَ نَنسَاهُمْ كَمَا نَسُواْ لِقَاء يَوْمِهِمْ هَـذَا...

That day shall We forget them as they forgot the meeting of this day of theirs,

C1029. "Forgetfulness" may be involuntary, from a defect of memory, or figuratively, a deliberate turning away from, or ignoring of, something we do not want, as when we say in an argument, "you conveniently forget that so- and-so is so-and-so." Here the latter kind is meant.

If men deliberately ignored the Hereafter in spite of warnings, can they expect to be received by Allah, Whom they themselves rejected?

...وَمَا كَانُواْ بِآيَاتِنَا يَجْحَدُونَ ﴿٥١﴾

and as they were wont to reject Our signs.

وَلَقَدْ جِئْنَاهُم بِكِتَابٍ فَصَّلْنَاهُ عَلَى عِلْمٍ...

7:52. For We had certainly sent unto them a Book, based on knowledge, which We explained in detail,

...هُدًى وَرَحْمَةً لِّقَوْمٍ يُؤْمِنُونَ ﴿٥٢﴾

a guide and a mercy to all who believe.