Key Verses

1. 4:31An-NisaConsolation
   إِن تَجۡتَنِبُواْ كَبَآئِرَ مَا تُنۡهَوۡنَ عَنۡهُ نُكَفِّرۡ عَنكُمۡ سَيِّـَٔاتِكُمۡ وَنُدۡخِلۡكُم مُّدۡخَلٗا كَرِيمٗا
   If ye avoid the great (things) which ye are forbidden, We will remit from you your evil deeds and make you enter at a noble gate.
   In context

   O believers, if you avoid the major sins, such as worshipping others gods with Allah, disrespecting your parents, killing, and receiving interest on loans, then Allah will forgive you for smaller sins, wiping them out and erasing them. Then Allah will enter you into a noble place near to Him: Paradise.

2. 42:37Ash-ShuraCommand
   وَٱلَّذِينَ يَجۡتَنِبُونَ كَبَـٰٓئِرَ ٱلۡإِثۡمِ وَٱلۡفَوَٰحِشَ وَإِذَا مَا غَضِبُواْ هُمۡ يَغۡفِرُونَ
   And those who shun the worst of sins and indecencies and, when they are wroth, forgive,
   In context

   Those who distance themselves from major and offensive sins and when they are angry at those who offend them by words or deeds they forgive their mistake and do not punish them for it. This pardon is a grace they offer when there is goodness and benefit in it.

3. 53:32An-Najm
   ٱلَّذِينَ يَجۡتَنِبُونَ كَبَـٰٓئِرَ ٱلۡإِثۡمِ وَٱلۡفَوَٰحِشَ إِلَّا ٱللَّمَمَۚ إِنَّ رَبَّكَ وَٰسِعُ ٱلۡمَغۡفِرَةِۚ هُوَ أَعۡلَمُ بِكُمۡ إِذۡ أَنشَأَكُم مِّنَ ٱلۡأَرۡضِ وَإِذۡ أَنتُمۡ أَجِنَّةٞ فِي بُطُونِ أُمَّهَٰتِكُمۡۖ فَلَا تُزَكُّوٓاْ أَنفُسَكُمۡۖ هُوَ أَعۡلَمُ بِمَنِ ٱتَّقَىٰٓ
   Those who avoid enormities of sin and abominations, save the unwilled offences - (for them) lo! thy Lord is of vast mercy. He is Best Aware of you (from the time) when He created you from the earth, and when ye were hidden in the bellies of your mothers. Therefor ascribe not purity unto yourselves. He is Best Aware of him who wardeth off (evil).
   In context

   Those who stay away from major sins and evil wrongs, besides minor sins as these are forgiven by leaving out the major ones and by an abundance of good deeds. Your Lord, O Messenger, is of vast forgiveness. He forgives the sins of His servants when they repent from them.