An-Nisa' - 4:18

وَلَيْسَتِ التَّوْبَةُ لِلَّذِينَ يَعْمَلُونَ السَّيِّئَاتِ حَتَّى إِذَا حَضَرَ أَحَدَهُمُ الْمَوْتُ قَالَ إِنِّي تُبْتُ الآنَ وَلاَ الَّذِينَ يَمُوتُونَ وَهُمْ كُفَّارٌ أُوْلَـئِكَ أَعْتَدْنَا لَهُمْ عَذَابًا أَلِيمًا
[4:18]
And repentance is not for those who go on doing evil deeds, until when death comes to one of them, he says: Surely now I repent; nor (for) those who die while they are unbelievers. These are they for whom We have prepared a painful chastisement.
Of no effect is the repentance of those who continue to do evil, until death faces one of them, and he says, "Now have I repented indeed;" nor of those who die rejecting Faith: for them have We prepared a punishment most grievous.
The forgiveness is not for those who do ill-deeds until, when death attendeth upon one of them, he saith: Lo! I repent now; nor yet for those who die while they are disbelievers. For such We have prepared a painful doom.