Allah the Exalted said,

[يأَيُّهَا الَّذِينَ ءَامَنُواْ تُوبُواْ إِلَى اللَّهِ تَوْبَةً نَّصُوحاً]

(O you who believe! Turn to Allah with sincere repentance!) meaning, a true, firm repentance that erases the evil sins that preceded it and mend the shortcoming of the repenting person, encouraging and directing him to quit the evil that he used to do. Allah said,

[عَسَى رَبُّكُمْ أَن يُكَفِّرَ عَنكُمْ سَيِّئَـتِكُمْ وَيُدْخِلَكُمْ جَنَّـتٍ تَجْرِى مِن تَحْتِهَا الاٌّنْهَـرُ]

(It may be that your Lord will expiate from you your sins, and admit you into Gardens under which rivers flow) And when Allah says, "it may be,'' it means He shall.

[يَوْمَ لاَ يُخْزِى اللَّهُ النَّبِىَّ وَالَّذِينَ ءَامَنُواْ مَعَهُ]

(the Day that Allah will not disgrace the Prophet and those who believe with him) meaning, on the Day of Resurrection, Allah will not disgrace those who believed in the Prophet ,

[نُورُهُمْ يَسْعَى بَيْنَ أَيْدِيهِمْ وَبِأَيْمَـنِهِمْ]

(Their light will run forward before them and in their right hands.) as we explained in Surat Al-Hadid,

[يَقُولُونَ رَبَّنَآ أَتْمِمْ لَنَا نُورَنَا وَاغْفِرْ لَنَآ إِنَّكَ عَلَى كُلِّ شَىْءٍ قَدِيرٌ]

(They will say:"Our Lord! Keep perfect our light for us and grant us forgiveness. Verily, You are Able to do all things.'') Mujahid, Ad-Dahhak and Al-Hasan Al-Basri and other said, "This is the statement that the believers will say on the Day of Resurrection, when they witness the light of the hypocrites being extinguished.'' Imam Ahmad recorded that a man from the tribe of Banu Kinanah said, "I prayed behind the Messenger of Allah during the year of the Conquest (of Makkah), and heard him say,

«اللْهُمَّ لَا تُخْزِنِي يَوْمَ الْقِيَامَة»

(O Allah! Please, do not disgrace me on the Day of Resurrection.)''

[يأَيُّهَا النَّبِىُّ جَـهِدِ الْكُفَّارَ وَالْمُنَـفِقِينَ وَاغْلُظْ عَلَيْهِمْ وَمَأْوَاهُمْ جَهَنَّمُ وَبِئْسَ الْمَصِيرُ - ضَرَبَ اللَّهُ مَثَلاً لِّلَّذِينَ كَفَرُواْ امْرَأَتَ نُوحٍ وَامْرَأَتَ لُوطٍ كَانَتَا تَحْتَ عَبْدَيْنِ مِنْ عِبَادِنَا صَـلِحَيْنِ فَخَانَتَاهُمَا فَلَمْ يُغْنِينَا عَنْهُمَا مِنَ اللَّهِ شَيْئاً وَقِيلَ ادْخُلاَ النَّارَ مَعَ الدَخِلِينَ ]

(9. O Prophet! Strive hard against the disbelievers and the hypocrites, and be severe against them; their abode will be Hell, and worst indeed is that destination.) (10. Allah sets forth an example for those who disbelieve: the wife of Nuh and the wife of Lut. They were under two of our righteous servants, but they both betrayed them. So, they availed them not against Allah and it was said: "Enter the Fire along with those who enter!'')