يَا أَيُّهَا الَّذِينَ آمَنُوا كُلُوا مِن طَيِّبَاتِ مَا رَزَقْنَاكُمْ وَاشْكُرُوا لِلَّهِ إِن كُنتُمْ إِيَّاهُ تَعْبُدُونَ
O you who believe! Eat from the good things We have provided for you. and be grateful to Allah, if it is He whom you worship.
-Quran 2:172
According to Islam, one of our foremost duties is to be grateful to God for all of His blessings. We can describe three levels of thankfulness:
To realize and appreciate all blessings by and within the heart.
To say thanks with the tongue.
To express gratitude by doing righteous deeds.
In other words, the first level is the appreciativeness and gratefulness that we feel in our hearts. Then we fortify that thankfulness through our speech. And the third level is when we prove by our deeds that we are truly thankful to God.