[1] The work is considered as an indispensable reference book for those who study and specialize in Islamic mysticism, since it combines the two genres of biographical hagiography and technical manual – a feature that no other text from the period displays.

The work may be divided as follows:[3] Al-Qushayri took it as axiomatic that the beliefs of the Sufi shaykhs were "in agreement with Sunni teaching on questions of the fundamentals of faith (Usul al-Din)".

"[8] The first French translation was by André Fontenay, and it was printed and published in 2016 under the title "Épître sur la science du soufisme.

[10] Taj al-Din al-Subki (d. 771/1370) in his book Mu'id al-Ni'am wa Mubid al-Niqam (Arabic: معيد النعم ومبيد النقم, lit.

'Restorer of Graces and Annihilator of Misfortunes') praised the creed of al-Qushayri, who mentioned it in his epistle, and considered it as one of the most important classical Sunni creeds held by the Ash'aris, along with al-'Aqida al-Tahawiyya by the Hanafi scholar Abu Ja'far al-Tahawi (d. 321/933), and al-'Aqida al-Murshida [ar] by Ibn Tumart (d. 524/1130), the founder of the Almohad Empire in North Africa and al-Andalus, who was a student of al-Ghazali.