Worthlessness of deeds without faith and sincere intention

وَٱلَّذِينَ كَفَرُوٓا۟ أَعْمَـٰلُهُمْ كَسَرَابٍۭ بِقِيعَةٍ يَحْسَبُهُ ٱلظَّمْـَٔانُ مَآءً حَتَّىٰٓ إِذَا جَآءَهُۥ لَمْ يَجِدْهُ شَيْـًٔا وَوَجَدَ ٱللَّهَ عِندَهُۥ فَوَفَّىٰهُ حِسَابَهُۥ ۗ وَٱللَّهُ سَرِيعُ ٱلْحِسَابِ

But those who disbelieved - their deeds are like a mirage in a lowland which a thirsty one thinks is water until, when he comes to it, he finds it is nothing but finds Allāh before him, and He will pay him in full his due; and Allāh is swift in account.