Source : http://islamicinsights.com/religion/religion/gratefulness-the-essence-of-islam.html
One of the best gifts Allah swt has granted mankind is the ability to feel and express gratitude. Being grateful at the most basic level is very simple and very beneficial. It is simple because it requires no special knowledge, skill, equipment, or preparation - anyone can access the gift of thankfulness. Yet most of us fall short of the mark in expressing due thanks for what others do, and probably all of us owe far more thanks to Allah (swt) than we even understand. However, improvement is also simple: just make it a practice to notice blessings and kindnesses, to think about them, and to honor them.
One reason gratitude is beneficial is because it improves relationships, - whether interpersonal or with our Creator. When we can feel and express appreciation for God's blessings or other's kindnesses, affection grows. But the personal benefits are also great; a thankful heart is a content and awed heart. Even in times and circumstances of hardship, we always have much to appreciate. When we acknowledge this, our burdens are easier to bear.
Imam Sadiq (as) wrote in Lantern of the Path,
"With every breath you take, a thanksgiving is incumbent upon you, indeed, a thousand thanks or more. The lowest level of gratitude is to see that the blessing comes from Allah irrespective of the cause for it, and without the heart being attached to that cause. It consists of being satisfied with what is given; it means not disobeying Him with regard to His blessing, or opposing Him in any of His commands and prohibitions because of His blessing."
Our breathing comes without thought, and yet each breath is a blessing. The struggle for breath is an agony that we are usually spared thousands upon thousands of times without thanking for it. If the gift of breath is taken from us, we will die; breath is life. It is but one of countless examples of blessings from God we owe thanks for. At the very least, we should appreciate that it is a gift from God, be satisfied with the gift, and never use the gift of breath for anything opposing Allah swt. One could possibly say that if we truly wish to express gratitude for the gift of breath, we must never allow ourselves to purposely breathe in any haram substances and we must never use our breath to utter any lies, backbiting, or other haram speech. For even if we claim to feel gratitude, the proof of real thankfulness comes in our actions. If we are thankful for a gift, we will not be careless with it. If someone gave you a birthday present you really loved, you would use it with caution in order to protect it. Similarly, if we are truly grateful for the blessing of breath, we will use it with caution, too.
Imam Sadiq (as) continues:
"Be a grateful bondsman to Allah in every way, and you will find that Allah is a generous Lord in every way. If there were a way of worshipping Allah for His sincerest bondsman to follow more excellent than giving thanks at every instance, He would have ascribed to them the name of this worship above the rest of creation. Since there is no form of worship better than that, He has singled out this kind of worship from other kinds of worship, and has singled out those who practice this kind of worship, saying,
وَقَلِيلٌ مِّنْ عِبَادِيَ الشَّكُورُ
Very few of my servants are grateful. (34:13)
Expressing thanks to God is a great form of worship, and at the minimum is part of our daily prayers. Allah swt has taught us that when we give thanks, blessings increase. Not only is this true about the blessings directly from God, but it applies for gratitude to the blessings of Allah swt that come from people as well. For example, a child who demonstrates true appreciation for Eid gifts or quality time spent with daddy inspires the giver to happily continue to give to that child, while a child who seems to take a gift for granted or does not seem to like or appreciate it may find the giver less generous in the future. God is not in need of our thanks and is not hurt in the least by our ingratitude, but gratitude enriches us immeasurably. "Allah is not in need of the obedience of His bondsmen, for He has the power to increase blessings forever. Therefore be a grateful bondsman to Allah, and in this manner you will see wonders." (Ibid.)
Even feeling and expressing gratitude is itself a merciful blessing from God.
"Complete thankfulness is to sincerely repent your inability to convey the least amount of gratitude, and expressing this by means of your sincere glorification of Allah. This is because fitting thanks is itself a blessing bestowed upon the bondsman for which he must also give thanks; it is of greater merit and of a higher state than the original blessing which caused him to respond with thanks in the first place. Therefore, every time one gives thanks one is obliged to give yet greater thanks, and so on ad infinitum, and this while absorbed in His blessings and unable to achieve the ultimate state of gratitude. For how can the bondsman match with gratitude the blessings of Allah, and when will he match his own action with Allah's while all along the bondsman is weak and has no power whatsoever, except from Allah?" (Ibid.)
The world would be a better place if we were more grateful to Allah swt and to others. Therefore, I would like to publicly thank God for His continued mercy toward me, and to thank my parents for their love. Those few words are not adequate at all, but should not be left unsaid. I invite readers to use the comments section to thank Allah swt and/or any person.