What does the Quran say about gratitude?

وَإِذْ تَأَذَّنَ رَبُّكُمْ لَئِن شَكَرْتُمْ لَأَزِيدَنَّكُمْ ۖ وَلَئِن كَفَرْتُمْ إِنَّ عَذَابِى لَشَدِيدٌۭ

And [remember] when your Lord proclaimed, 'If you are grateful, I will surely increase you [in favor]; but if you deny, indeed, My punishment is severe.' "

فَٱذْكُرُونِىٓ أَذْكُرْكُمْ وَٱشْكُرُوا۟ لِى وَلَا تَكْفُرُونِ

So remember Me; I will remember you. And be grateful to Me and do not deny Me.

وَإِن تَعُدُّوا۟ نِعْمَةَ ٱللَّهِ لَا تُحْصُوهَآ ۗ إِنَّ ٱللَّهَ لَغَفُورٌۭ رَّحِيمٌۭ

And if you should count the favors of Allah, you could not enumerate them. Indeed, Allah is Forgiving and Merciful.

وَلَقَدْ ءَاتَيْنَا لُقْمَٰنَ ٱلْحِكْمَةَ أَنِ ٱشْكُرْ لِلَّهِ ۚ وَمَن يَشْكُرْ فَإِنَّمَا يَشْكُرُ لِنَفْسِهِۦ ۖ وَمَن كَفَرَ فَإِنَّ ٱللَّهَ غَنِىٌّ حَمِيدٌۭ

And We had certainly given Luqman wisdom [and said], "Be grateful to Allah." And whoever is grateful is grateful for [the benefit of] himself. And whoever denies [His favor] - then indeed, Allah is Free of need and Praiseworthy.

وَٱللَّهُ أَخْرَجَكُم مِّنۢ بُطُونِ أُمَّهَٰتِكُمْ لَا تَعْلَمُونَ شَيْـًۭٔا وَجَعَلَ لَكُمُ ٱلسَّمْعَ وَٱلْأَبْصَٰرَ وَٱلْأَفْـِٔدَةَ ۙ لَعَلَّكُمْ تَشْكُرُونَ

And Allah has extracted you from the wombs of your mothers not knowing a thing, and He made for you hearing and vision and intellect that perhaps you would be grateful.

فَبِأَىِّ ءَالَآءِ رَبِّكُمَا تُكَذِّبَانِ

So which of the favors of your Lord would you deny?

إِنَّا هَدَيْنَٰهُ ٱلسَّبِيلَ إِمَّا شَاكِرًۭا وَإِمَّا كَفُورًا

Indeed, We guided him to the way, be he grateful or be he ungrateful.