The Hereafter and the Day of Reckoning in the Qur'an

وَٱلَّذِينَ يُؤْمِنُونَ بِمَآ أُنزِلَ إِلَيْكَ وَمَآ أُنزِلَ مِن قَبْلِكَ وَبِٱلْـَٔاخِرَةِ هُمْ يُوقِنُونَ

And who believe in that which is revealed unto thee (Muhammad) and that which was revealed before thee, and are certain of the Hereafter.

وَنَضَعُ ٱلْمَوَٰزِينَ ٱلْقِسْطَ لِيَوْمِ ٱلْقِيَـٰمَةِ فَلَا تُظْلَمُ نَفْسٌ شَيْـًٔا ۖ وَإِن كَانَ مِثْقَالَ حَبَّةٍ مِّنْ خَرْدَلٍ أَتَيْنَا بِهَا ۗ وَكَفَىٰ بِنَا حَـٰسِبِينَ

And We set a just balance for the Day of Resurrection so that no soul is wronged in aught. Though it be of the weight of a grain of mustard seed, We bring it. And We suffice for reckoners.

أَفَحَسِبْتُمْ أَنَّمَا خَلَقْنَـٰكُمْ عَبَثًا وَأَنَّكُمْ إِلَيْنَا لَا تُرْجَعُونَ

Deemed ye then that We had created you for naught, and that ye would not be returned unto Us?

فَمَن يَعْمَلْ مِثْقَالَ ذَرَّةٍ خَيْرًا يَرَهُۥ

And whoso doeth good an atom's weight will see it then,

وَمَن يَعْمَلْ مِثْقَالَ ذَرَّةٍ شَرًّا يَرَهُۥ

And whoso doeth ill an atom's weight will see it then.