Opposition to Allah and His Messenger

ذَٰلِكَ بِأَنَّهُمْ شَآقُّوا۟ ٱللَّهَ وَرَسُولَهُۥ ۚ وَمَن يُشَاقِقِ ٱللَّهَ وَرَسُولَهُۥ فَإِنَّ ٱللَّهَ شَدِيدُ ٱلْعِقَابِ

That is because they opposed Allāh and His Messenger. And whoever opposes Allāh and His Messenger - indeed, Allāh is severe in penalty.