Quran 4, An-Nisa (the Women) ⓘ

4:115And whoso opposeth the messenger after the guidance (of Allah) hath been manifested unto him, and followeth other than the believer's way, We appoint for him that unto which he himself hath turned, and expose him unto hell - a hapless journey's end!

وَمَنْ يُشَاقِقِ الرَّسُولَ مِنْ بَعْدِ مَا تَبَيَّنَ لَهُ الْهُدَى وَيَتَّبِعْ غَيْرَ سَبِيلِ الْمُؤْمِنِينَ نُوَلِّهِ مَا تَوَلَّى وَنُصْلِهِ جَهَنَّمَ وَسَاءَتْ مَصِيرًا

4:116Lo! Allah pardoneth not that partners should be ascribed unto Him. He pardoneth all save that to whom He will. Whoso ascribeth partners unto Allah hath wandered far astray.

إِنَّ اللَّهَ لَا يَغْفِرُ أَنْ يُشْرَكَ بِهِ وَيَغْفِرُ مَا دُونَ ذَلِكَ لِمَنْ يَشَاءُ وَمَنْ يُشْرِكْ بِاللَّهِ فَقَدْ ضَلَّ ضَلَالًا بَعِيدًا