Bismillāh.
وَلَا تَكُونُوا كَالَّذِينَ نَسُوا اللَّهَ فَأَنسَاهُمْ أَنفُسَهُمْ ۚ أُولَٰئِكَ هُمُ الْفَاسِقُونَ
And be not like those who forgot Allah, so He made them forget themselves.
(Surat al-Hashr, No.59, Āyat 19)
When a person forgets Allah ‘azza wajall and distances himself from his Creator, he forgets the entire purpose of being on this earth. All his efforts, hopes and desires revolve around this world. Essentially, he forgets his ‘insāniyat’or what it means to be human. This curtain is a direct result of forgetting Allah, a step that the human being initiates himself.
To forget is to know something at one time but then to lose that knowledge. A person who forgets Allah knew Him in the first place but overlooked it. This initial knowledge is present in the instinct of the human being. It resides deep inside him but gets covered through exposure to material aspects of this world. It could surface again if Allah and the hereafter are remembered. The greater the indulgence in worldly occupations, the thicker the veil over the remembrance of Allah.
According to ‘Allāmah Tabātabā’ī in Tafsīr al-Mīzān the human being forgetting himself means that he forgets the beautiful names of Allah and His noble qualities that are manifested in his own essence. He overlooks the fact that he is a servant of Allah and very needy of Him. Such a perceived independence from Allah makes him feel he is in complete control of his life. He sees all things as independent causes. Selfishness and arrogance creep into his soul and cover his intellect. He is oblivious of the return to God. Slowly he loses all trace of the original potential he had of being the most noble of creation.
The warning of not being forgetful of the true self is made through the warning to not forget Allah. It is the remembrance of Allah that awakens the noble spirit in the human being and triggers an upwards ascension of the soul. Without that remembrance the human being descends to become a lowly creature who has lost the distinctive features that were given to him. Forgetting the true nature of oneself is the biggest spiritual disaster to fall the human being. Such a person becomes oblivious of all that made him the best of creation. The Quran talks about how the Almighty announced the creation of the human being to the angels:
– I am placing a vicegerent on earth (Q 2:30)
– Indeed, I am going to create a human out of a dry clay [drawn] from an aging mud. So, when I have proportioned him and breathed into him of My spirit, then fall down in prostration before him. (Q 15:28-29)
These and other verses show the esteemed position of the human being. To forget that is to lose the treasure within him. The status he could have achieved slips away.
Remembrance of Allah has been highlighted in hadith as the cure for all inner diseases. Imam Ali (a) says:
Certainly, Allah, the Glorified, the Sublime, has made His remembrance the light for hearts which hear with its help despite deafness, see with its help despite blindness and become submissive with its help despite unruliness . . . There are some people devoted to the remembrance (of Allah) who have adopted it in place of worldly matters so that commerce or trade does not turn them away from it. They pass their life in it. (Nahjul Balāghah, Sermon 221)
The emphasis in Islam on remembrance of Allah is to help the human being remember his own greatness. Obligatory acts like the prayer and recommended acts such as supplications etc. all help the human being walk firm on the path towards perfection. Without the remembrance of Allah, it is possible to fall quickly to become more animal-like than human.
Sources: Allāmah Muhammad Husayn Tabātabā’ī, Tafsīr al-Mīzān; Āyatullāh Nāsir Makārim Shirāzī (editor), Tafsīr-e Namūneh; http://tadabbor.org/?page=tadabbor&SOID=59&AYID=19&TPIV=T2