Allah the Exalted states here that the believers and the disbelievers are never equal. Allah said in another Ayah,

لاَ يَسْتَوِى أَصْحَـبُ النَّارِ وَأَصْحَـبُ الْجَنَّةِ أَصْحَـبُ الْجَنَّةِ هُمُ الْفَآئِزُونَ

(Not equal are the dwellers of the Fire and the dwellers of the Paradise. It is the dwellers of Paradise that will be successful.) (59:20) Allah said here,

أَمْ حَسِبَ الَّذِينَ اجْتَرَحُواْ السَّيِّئَـتِ

(Or do those who earn evil deeds think) those who commit and practice evil,

أَن نَّجْعَلَهُمْ كَالَّذِينَ ءَامَنُواْ وَعَمِلُواْ الصَّـلِحَـتِ سَوَآءً مَّحْيَـهُمْ وَمَمَـتُهُمْ

(that We shall hold them equal with those who believe and do righteous good deeds, in their life and their death) treat them equally in the present life of the world and in the Hereafter

سَآءَ مَا يَحْكُمُونَ

(Worst is the judgement that they make.) `worst is the thought that they have about Us and about Our justice, thinking that We will ever make the pious and the wicked equal in the Hereafter or this life.' At--Tabarani recorded that Shu`bah said that `Amr bin Murrah narrated that Abu Ad-Duha said that Masruq said that Tamim Ad-Dari once stood in voluntary prayer through the night until the morning only reciting this Ayah,

أَمْ حَسِبَ الَّذِينَ اجْتَرَحُواْ السَّيِّئَـتِ أَن نَّجْعَلَهُمْ كَالَّذِينَ ءَامَنُواْ وَعَمِلُواْ الصَّـلِحَـتِ

(Or do those who earn evil deeds think that We shall hold them equal with those who believe and do righteous good deeds) Allah said in reply:

سَآءَ مَا يَحْكُمُونَ

(Worst is the judgement that they make.) Allah said,

وَخَلَقَ اللَّهُ السَّمَـوَتِ وَالاٌّرْضَ بِالْحَقِّ

(And Allah has created the heavens and the earth with truth,) meaning, in justice,

وَلِتُجْزَى كُلُّ نَفْسٍ بِمَا كَسَبَتْ وَهُمْ لاَ يُظْلَمُونَ

(in order that each person may be recompensed what he has earned, and they will not be wronged.) Allah the Exalted said,

أَفَرَأَيْتَ مَنِ اتَّخَذَ إِلَـهَهُ هَوَاهُ

(Have you seen him who takes his own lust as his god), who abides by his lust, and whatever his lust portrays as good he implements it, and whatever his lust portrays as evil, he abandons it! Allah's statement,

وَأَضَلَّهُ اللَّهُ عَلَى عِلْمٍ

(And Allah left him astray with knowledge, ) has two meanings. One of them is that Allah knew that this person deserves to be misguided, so He left him astray. The second meaning is that Allah led this person astray after knowledge reached him and the proof was established before him. The second meaning includes the first meaning, but not the opposite. Allah said,

وَخَتَمَ عَلَى سَمْعِهِ وَقَلْبِهِ وَجَعَلَ عَلَى بَصَرِهِ غِشَـوَةً

(and sealed his hearing and his heart, and put a cover on his sight.) so he does not hear what benefits him, understands not what would lead him to the guidance and sees not the evidence with which he can be enlightened. This is why Allah said,

فَمَن يَهْدِيهِ مِن بَعْدِ اللَّهِ أَفَلاَ تَذَكَّرُونَ

(Who then will guide him after Allah Will you not then remember) Allah said in a similar Ayah,

مَن يُضْلِلِ اللَّهُ فَلاَ هَادِيَ لَهُ وَيَذَرُهُمْ فِى طُغْيَـنِهِمْ يَعْمَهُونَ

(Whomsoever Allah sends astray, none can guide him; and He lets them wander blindly in their transgressions.) (7:186).