Qur'an 2:217

يَسْـَٔلُونَكَ عَنِ ٱلشَّهْرِ ٱلْحَرَامِ قِتَالٍ فِيهِ ۖ قُلْ قِتَالٌ فِيهِ كَبِيرٌ ۖ وَصَدٌّ عَن سَبِيلِ ٱللَّهِ وَكُفْرٌۢ بِهِۦ وَٱلْمَسْجِدِ ٱلْحَرَامِ وَإِخْرَاجُ أَهْلِهِۦ مِنْهُ أَكْبَرُ عِندَ ٱللَّهِ ۚ وَٱلْفِتْنَةُ أَكْبَرُ مِنَ ٱلْقَتْلِ ۗ وَلَا يَزَالُونَ يُقَـٰتِلُونَكُمْ حَتَّىٰ يَرُدُّوكُمْ عَن دِينِكُمْ إِنِ ٱسْتَطَـٰعُوا۟ ۚ وَمَن يَرْتَدِدْ مِنكُمْ عَن دِينِهِۦ فَيَمُتْ وَهُوَ كَافِرٌ فَأُو۟لَـٰٓئِكَ حَبِطَتْ أَعْمَـٰلُهُمْ فِى ٱلدُّنْيَا وَٱلْـَٔاخِرَةِ ۖ وَأُو۟لَـٰٓئِكَ أَصْحَـٰبُ ٱلنَّارِ ۖ هُمْ فِيهَا خَـٰلِدُونَ

“They ask you about the sacred month - about fighting therein. Say, "Fighting therein is great [sin], but averting [people] from the way of Allāh and disbelief in Him and [preventing access to] al-Masjid al-Ḥarām and the expulsion of its people therefrom are greater [evil] in the sight of Allāh. And fitnah is greater than killing." And they will continue to fight you until they turn you back from your religion if they are able. And whoever of you reverts from his religion [to disbelief] and dies while he is a disbeliever - for those, their deeds have become worthless in this world and the Hereafter, and those are the companions of the Fire; they will abide therein eternally.”

Al-Baqara 2:217 · Saheeh International