The Messenger of Allah [SAW] said: "Whoever comes worshipping Allah and not associating anything with Him, establishing Salah, paying Zakah and avoiding major sins, Paradise will be his." They asked him about major sins and he said: "Associating others with Allah, killing a Muslim soul, and fleeing (from the battlefield) on the day of the march." (Using translation from Nasāʾī 4009)
أَنَّ رَسُولَ اللهِ ﷺ يَقُولُ «مَنْ جَاءَ اللهَ يَعْبُدُهُ وَلَا يُشْرِكُ بِهِ شَيْئًا وَأَقَامَ الصَّلَاةَ وَآتَى الزَّكَاةَ وَصَامَ رَمَضَانَ وَاجْتَنَبَ الْكَبَائِرَ فَإِنَّ لَهُ الْجَنَّةَ» فَسَأَلُوهُ وَمَا الْكَبَائِرُ؟ فَقَالَ «الْإِشْرَاكُ بِاللهِ وَقَتْلُ النَّفْسِ الْمُسْلِمَةِ وَفِرَارٌ يَوْمَ الزَّحْفِ»