Islahi was born in 1904 at Bamhur, a small village in Azamgarh (U.P.), India. He received his early education in two local schools of the village. His father Hafiz Muhammad Murtaza was a small landlord of the area. Islahi was admitted to Madrasah "Al-Islah" in 1915 in grade three. This Madrasah is located in Sarai-Mir a small village near Bamhore. It was while addressing the convocation ceremony of the first batch of the Madrasah that he first came in the notice of the great Hamid Uddin Farahi, the person who was destined to become his mentor and guide.  
    The teacher which influenced him the most during his student life at the Madrasah was Mawlana Abdu’l Rahman Nigrami, himself a versatile genius. Mawlana Nigrami’s attention helped him in developing a profound inclination towards Arabic literature. After graduating from the Madrasah in 1922, he entered the field of journalism. For a while he edited a newspaper "Madinah" at Bijnawr and also remained associated with "Sach", a newspaper taken out by Mawlana Abdu’l Majid Daryabadi.  
    It was sometime in 1925 when Farahi offered Islahi to come and study the Qur’an with him. Islahi abandoned his journalistic career with no hesitation at all to benefit from this glorious opportunity. He knew he had stumbled upon the `famous tide’: --- ‘the tide in the affairs of men which when taken at the flood leads on to good fortune’. For the next five years till Farahi’s death in 1930, he remained with him like his shadow. It was in this forming period of his life in which he developed a deep understanding of the Qur’an and learnt from Farahi the principles of direct deliberation on the Book of Allah. During this time, he also taught the Qur’an and Arabic literature at the Madrasah.  
    After Farahi’s death, Islahi studied Hadith from a celebrated scholar of this discipline, Abdu’l Rahman Muhaddith Mubarakpuri. In 1936, he founded the "Daira-i-Hamidiyyah", a small institute to disseminate the Qur’anic thought of Farahi. Under the auspices of this institute, he brought out a monthly journal "Al-Islah" in which he translated many portions of Farahi’s treatises written in Arabic. The journal was published till 1939, after which it was discontinued.  
    Islahi was among the founder members of the "Jama`at-i-Islami", a religious party founded by the eminent Islamic scholar Mawdudi in 1941. During his seventeen year stay in the Jama`at, he represented the intellectual element and remained a member of the central governing body (Majlis-i-Shura). During this period, he did the groundwork needed to write a commentary of the Qur’an – an objective which he had set before him early in life. In 1958, he abandoned the Jama`at, after serious differences arose between him and Mawdudi on the nature of the constitution of the Jama`at.  
        After leaving the Jama`at, he finally got the chance to fulfil his cherished goal of writing a commentary of the Qur’an. He also launched a monthly journal "Mithaq" in which portions of this commentary, "Tadabbur-i-Qur’an" were published. In 1961, he established a small study circle "Halqa-i-Tadabbur-i- Qur’an" for college students to whom he taught Arabic language and literature, the Holy Qur’an and "Sahih Muslim". In 1965, a tragic incident brought an end to the journal as well as to the study circle: Islahi’s eldest son Abu Saleh died in a plane . However, work on the commentary continued. In 1970-71, Islahi fell severely ill and had to discontinue all his intellectual pursuits. Subsequently, he recovered quite miraculously. In 1972, he shifted to a countryside village near Sheikhupura, where he continued to work on the commentary till 1979, when he shifted back to Lahore. It was on the 29th of Ramadan 1400/ 12th August 1980 when the great day arrived – the day when a monumental effort reached its culmination. The "Tadabbur-i-Qur’an" had taken twenty-two long years to complete.  
    In 1981 Islahi founded the "Idara-i-Tadabbur-i-Qur’an-o-Hadith", which remained until his death (15th December 1997) the centre of all his intellectual activities. A quarterly journal "Tadabbur" was taken out in 1981 as its organ. He gave weekly lectures on the text of the Qur’an. Later, he took up deep study on the principles of Hadith and began teaching the "Mu`atta" of Imam Malik in weekly sittings to a close circle of students and associates. After completing "Mu’atta", he also taught some portions of Imam Bukhari’s "Sahih". Many of these lectures have been transcribed and published in the "Tadabbur".  
    Besides writing the "Tadabbur-i-Qur’an", Islahi has written a number of articles and authored a number of books on various topics of Islam. They include:  
 
    1. Tazkiyah-i-Nafs (Purification of the Soul)  
    2. Mubadi Tadabbur-i-Qur’an (Principles of Understanding the Qur’an)  
    3. Haqiqat-i-Shirk-o-Tawhid  (The Essence of Polytheism and Monotheism)  
    4. Da`wat-i-Din Awr us ka Tariqa-i-Kar (Islamic Message and the mode of its Preaching)  
    5. Islami Qanun ki Tadwin (Codification of Islamic Law)  
    6. Islami Riyasat (Islamic State)  
    7. Islami Mu`asharay mayn Awrat ka Muqavm (The Status of Women in an Islamic Society)  
    8. Haqiqat-i-Namaz  (Essence of the Prayers)  
    9. Haqiqat-i-Taqwah (Essence of Godliness)  
    10. Islami Riyasat mayn Fiqhi Ikhtilafat ka Hal (Solution of Juristic Differences in an Islamic  State)  
    11. Mubadi Tadabbur-i-Hadith (Principles of Understanding the Hadith)  
    12. Tanqidat (A collection of critical essays)  
    13. Tawdihat (A collection of general explanatory essays)  
    14. Maqalat-i-Islahi (Miscellaneous collection of articles)  
    15. Qur’an mayn Pardah kay Ahkamat (The Directives of Purdah in the Qur’an)  
    16. Tafhim-i-Din (Understanding Islam)  
    17. Falsafay kay Mathail Qur’an ki Rawshani mayn (Basic Philosophical Issues in the Light of the Qur’an)  
 
    Islahi also translated Farahi’s commentary consisting of fourteen surahs of the Qur’an, as well as his following books from Arabic:  
    1. Fi man huwa al-dhabih (Which of Abraham’s son was Sacrificed?)  
    2. Aqsamu’l Qur’an (Oaths in the Qur’an)  

        Mr Khalid Masud, Mr Mahbub Subhani, Mr Javed Ahmad Ghamidi, Mr Mahmud Ahmad Lodhi, Mr Majid Khawar, Mr Abullah Ghulam Ahmad, Mr Saeed Ahmad and Mr Muhammad Daud are some of his notable students in Pakistan.