Allah Most High said:
{Kamaa arsalnaa fikum rasoolan minkum yatloo 'alaikum aayaatinaa wa yuzakkeekum wa yu'allimukum al-kitaaba wa al-hikmata wa yu'allimukum maa lam takunoo ta'lamoon. (151) Fadhkurooniy adhkurkum washkuroo liy wa laa takfuroon. (152)}
{Just as we sent among you a messenger from you who recites to you our signs, purifies you and teaches you the book and the wisdom and teaches you that which you did not know. (151) So remember me so I remember you and give thanks to me and do not disbelieve. (152)} Al-Baqarah:151-152
This verse tells us many things about the mission of the messengers and our obligation of gratitude toward Allah, among them:
The meaning of ash-shukr (thanks or gratitude) is: "An act which expresses magnification of the bestower because of what he has bestowed upon the one showing gratitude or upon others." Part of showing gratitude to Allah is: "Directing all that we are given to its intended purpose and utilizing it in the ways which Allah has prescribed in His shari'a."
There are two kinds of shukr:
One of the main ways which we express shukr (gratitude) to Allah is be saying "Al-hamdu lillahi" But, what is the meaning of alhamdulillah? It is usually translated as, 'All praise is due to Allah.' Which has led many of us to use the phrase, Alhamdulillahi wa ash-shukru lillahi.' But this is incorrect because alhamdulillah is actually is a word of praise that includes within it a greater gratitude or shukr for what Allah has ordained, and as Muslims, we are supposed to use it when we are presented with that which appears good and with that which appears bad. Praise is called madhu or thanaa' and gratitude is called shukru as we have seen. Al-hamdu is a word which includes all of these meanings. The "Al" in Al-hamdu lillahi is what is called in Arabic grammer "al lil-jinsi", i.e., al-hamdu here means the entire category or everything which is hamdun. From this we get the translation "All ____ is due to Allah."
Listen to what Allah tells us about the people of paradise - may He make us among them:
{Da'waahum feeha 'subhaanaka Allahumma' wa tahiyyatuhum feeha 'salaamun'. Wa aakhiru da'waahum an il-hamdu lillahi rabbi al-'aalaameen.}
{Their call therein is 'Exalted are You O Allah' and their greeting therein is 'Peace'. And the end of their call is that all praise/gratitude is to Allah, Lord of the worlds.} Yunus:10
Likewise, just as showing gratitude to Allah for His many favors through obedience and using those favors as Allah would love to have them used, to fail to show gratitude to Allah is akin to disbelieving and leads to the punishment of Allah's fire. Allah said:
{Wa idhaa ta'adh-dhana rabbukum la'in shakartum la azeedannakum wa la'in kafartum inna 'adhaabiy la shadeedun.}
{And when your Lord announced that if you show gratitude I will increase you and if you disbelieve, verily My punishment is severe.} Ibrahim:7
Allah is in no need of anything from us and yet Allah Himself will express gratitude to the pious among His slaves in this life and in the hereafter. There is a close relationship between the nature of our relationship with Allah and our relationship with other people and they cannot be separated. Allah refers to sadaqa (giving to those in need) and qardh (loaning money to one in need in a lawful way) as "loans" which we give to Allah Himself. The payback for these "loans" is many times what we have sent forth and Allah himself will give us His gratitude!
{Fa ittaqoo Allaha maa istata'tum wasma'oo wa atee'oo wa anfiqoo khairan li anfusikum. Wa man yooqa shuhha nafsihi fa ulaa'ika hum al-muflihoon (16) In tuqridhoo Allaha qardhan hasanan yudhaa'ifhu lakum wa yaghfir lakum wa Allahu Shakoorun Haleemun. (17) 'Aalimu al-ghaibi wa ash-shahaadati al-'azeezu al-hakeemu. (18)}
{So, beware of Allah as much as you are able and listen and obey and give - that is better for you. And, whoever is protected from his own greed, these are the successful ones. (16) If you loan to Allah a good loan, He will multiply it for you and fogive you and Allah is most Grateful, most Compassionate. (17) The Knower of the unseen and the seen, the Mighty, the Wise. (18)} At-Taghaabun:16-18
One who give thanks to Allah will not stray from showing gratitude to people. Acts of giving to one another are an essential element in bringing the hearts together and bringing Allahs' blessing on us all.
Bukhl (miserliness) is a disease and a contagious one in society. This is because the bukhalaa cannot tolerate others who are not upon their evil way. They need others to be upon their way so their ugliness does not stand out so much. This stands in opposition to iman and to a healthy Muslim society. Allah said:
وَاعْبُدُوا اللَّهَ وَلَا تُشْرِكُوا بِهِ شَيْئًا وَبِالْوَالِدَيْنِ إِحْسَانًا وَبِذِي الْقُرْبَى وَالْيَتَامَى وَالْمَسَاكِينِ وَالْجَارِ ذِي الْقُرْبَى وَالْجَارِ الْجُنُبِ وَالصَّاحِبِ بِالْجَنْبِ وَابْنِ السَّبِيلِ وَمَا مَلَكَتْ أَيْمَانُكُمْ إِنَّ اللَّهَ لَا يُحِبُّ مَنْ كَانَ مُخْتَالًا فَخُورًا (36) الَّذِينَ يَبْخَلُونَ وَيَأْمُرُونَ النَّاسَ بِالْبُخْلِ وَيَكْتُمُونَ مَا آتَاهُمُ اللَّهُ مِنْ فَضْلِهِ وَأَعْتَدْنَا لِلْكَافِرِينَ عَذَابًا مُهِينًا (37)
{Worship Allâh and join none with Him (in worship); and do good to parents, kinsfolk, orphans, Al-Masâkîn (the poor), the neighbour who is near of kin, the neighbour who is a stranger, the companion by your side, the wayfarer (you meet), and those (slaves) whom your right hands possess. Verily, Allâh does not like such as are proud and boastful. (36) Those who are miserly and enjoin miserliness on other men and hide what Allâh has bestowed upon them of His Bounties. And We have prepared for the disbelievers a disgraceful torment.}
Miserliness is a self-defeating act. While it intends keeping good things to oneself, it brings nothing but evil and misery in this life and is a cause for punishment in the hereafter. Allah said:
وَلَا يَحْسَبَنَّ الَّذِينَ يَبْخَلُونَ بِمَا آتَاهُمُ اللَّهُ مِنْ فَضْلِهِ هُوَ خَيْرًا لَهُمْ بَلْ هُوَ شَرٌّ لَهُمْ سَيُطَوَّقُونَ مَا بَخِلُوا بِهِ يَوْمَ الْقِيَامَةِ وَلِلَّهِ مِيرَاثُ السَّمَاوَاتِ وَالْأَرْضِ وَاللَّهُ بِمَا تَعْمَلُونَ خَبِيرٌ (180)
{And let not those who covetously withhold of that which Allâh has bestowed on them of His Bounty (Wealth) think that it is good for them (and so they do not pay the obligatory Zakât ). Nay, it will be worse for them; the things which they covetously withheld shall be tied to their necks like a collar on the Day of Resurrection. And to Allâh belongs the heritage of the heavens and the earth; and Allâh is Well-Acquainted with all that you do.} Aal 'Imraan:180
Giving can include things, acts of kindness, help, sound advice and other things. Whoever doesn't recognize, acknowledge and appreciate good from Allah's creation will likely not recognize Allah's favors as well. Allah said:
If one benefits things, sound advice or any other form of good deed from another, they must acknowledge it and act upon it. In this way, our gratitude and mutual kindness among ourselves is an analogy for the relationship we need to have with Allah Most High. The Prophet (sas) said:
"... wa man ataa ilaikum ma'roofan fa kaafi'oohu fa in lam tajidoo fad'oo lahu hattaa ta'lamoo an qad laafa'tumoohu."
"...and whoever does you a good deed, recompense it. If you are unable than make du'a for him until you are sure that you have compensated him." Abu Daud & others
Because thanfulness and gratitude is a character trait, there is no way to separate having this character in one's relationship with Allah and having it in one's relationship with other people.
Those who have this character will look upon giving to others as a great opportunity for reward from Allah (manyfold), being given at some other time or, best of all, having that person make du'a to Allah for them. They will look upon being given something with humility, not as having "taken advantage" of someone, will thank Allah for putting generosity in the hearts of the Muslims and eagerly await his opportunity to repay the favor either in kind or by beseeching Allah on the giver's behalf. Likewise in their relationship with Allah Most High. They will look at every prohibition as a great gift of warning and guidance from Allah Most High and they will look at every obligation as an opportunity to express their gratitude to Allah for His enless favors upon us.
On the other hand, those who lack this character trait and have the traits of bukhl (miserliness), istighnaa' (thinking they are not in need of others) and takdheeb bi al-husnaa (they disacknowledge good) as mentioned in the above verses will have all the opposite traits. They will look at receiving good things from others either as a burden which they must repay or as a victory that they were the getters and not the givers. They will see generosity and giving as a burden and "being used". And again, likewise with Allah Most High. Just as the Prophet (sas) said about them in the hadith, they will see zakat as a fine or tax, prayer as physical exercise and Hajj as a picnic. Every prohibition to them is a restriction and every obligation is a burden. O Allah, grant us sound hearts which acknowledge good and love to give.
The Prophet (sas) said:
"Inna ashkaru an-naasi lillahi tabaaraka wa ta'aala ashkaruhum lin-naasi."
"The most grateful people to Allah Blessed and High are the most thankful of them to others." Ahmad
"Laa yashkuru Allaha man laa yashkuru an-naasi."
"Those who do not thank people do not thank Allah." Abu Daud & others