Allah, the Almighty said:

{…And few of My servants are grateful.} [Sabâ’ 34:13]

Gratefulness refers to the recognition of the bounties, as it is the way to recognizing their Bestower. Because of this, Allah, the Almighty, referred in the Qur’an to Islam and eemân as gratefulness.
There are three meanings for gratefulness: the recognition of the bounties, then their acceptance, and finally praising their Bestower.²⁹⁷ This is still from the paths of the common people.²⁹⁸
It is of three levels:

The first level is showing gratitude for desirables, and this type of gratefulness is shared by Muslims, Jews, Christians, and Zoroastrians. It is of the vastness of His mercy (exalted is He) that He considered it gratefulness, promised in return more bounties, and made it reward-worthy.

The second level is showing gratitude in distress. This is shown by one of two people: one to whom all situations are equal, and that is to show contentment; and one who discerns between the different situations, so as to suppress their rage, conceal their complaints, observe proper etiquette [with their Lord], and conform with the [revealed] knowledge. These grateful ones are the first to be invited to paradise.

The third level is when the servant beholds nothing but the Bestower of the bounties, so when he/she does that from the position of servitude, they will elevate the bounty; and from the position of love, they will find sweetness in difficulty (decreed) by Him; and from the position of tafreed (acknowledgment of His oneness), they will not recognize any bounty or hardship.²⁹⁹

²⁹⁷ Imam Ibn al-Qayyim mentions in Madârij that shukr rests on five foundations: submissiveness towards the One being thanked, loving Him, acknowledging His favor, praising Him for it, and using it only in that which He likes.
²⁹⁸Because in the sheikh’s view, all the stations short of self-annihilation are not befitting of the elite. When one reaches fanâ’, all one’s feelings will have been extinct, so they will not discern between bounties and calamities. As we said before, the fanâ’ that is sanctioned does not require the complete extinction of the self, which is impossible, but it requires the complete conformity to the will of God. That self will not be distracted by the awe of His glorification from complying with His injunctions and conforming to His will. Additionally, the station of shukr is the station of the most elite of all times, the messengers of Allah. Allah said about Nooḥ (peace be upon him):

{…Indeed, he was a grateful servant} (al-Isrâ’ 17:3)
and about Ibrâheem (peace be upon him):

{[He was] grateful for His favors...} (an-Naḥl 16:121)
and said to Muhammad ﷺ:

{Rather, worship [only] Allah and be among the grateful}, (az-Zumar 39:66)
who used to say to ‘Â’ishah when she wondered why he prayed until his feet cracked:

“Should I not prove myself to be a grateful servant (of Allah)?” (Agreed upon
²⁹⁹ Because all things are from the One (exalted is He). While all things are from Him and from that perspective they cannot be described as evil because His master plan is about goodness, they are still different from our angle: belief and disbelief, obedience and sin, justice and injustice, virtue and vice—they all exist in this world; they are different and they must not be reacted to with indifference. This is al-farq (discernment of the multiplicity of this world) that must be beheld with the jam‘ (the union with God, the One, the First Cause) at all times for proper realization of His demands from us.