Mahasha Malik Fazl Hussain belonged to a well-known family in Lahore. He accepted Ahmadiyyat at the age of 13 or 14. After facing severe opposition from his parents, he migrated to Qadian.

He had the opportunity to serve the Jamaat in various capacities. He served as the general secretary of the Local Anjuman Ahmadiyya Qadian and Anjuman Khuddam-ul-Islam. He also served as the manager of the Ahmadiyya Book Depot. 

For the propagation of Islam, Hazrat Mirza Bashiruddin Mahmud Ahmad (ra), Khalifatul Masih II, had instructed some scholars of the Jamaat to do research on other religions. Thus, Mahasha Malik Fazl Hussain was instructed to do research on Hinduism.

In 1922, Hazrat Mirza Bashiruddin Mahmud Ahmad (ra), Khalifatul Masih II, had appointed a team of scholars of the Jamaat to spread the message of Islam Ahmadiyyat to the ‘Untouchable Nations’. Thus, Mahasha Malik Fazl Hussain prepared a great literature in accordance with Huzoor’s instructions. 

In the early 1930s, he wrote a book, titled Hindu Raj Ke Mansubay [The Plans of the Hindu Rule], and included quotations of many Hindu leaders, to prove that they were planning to rule India through their political deceits and to suppress the Muslims’ rights. This book was much appreciated by the Muslim leaders of India, and got translated in many languages including English.

Some of his other books included Musalmanan-e-Kashmir Aur Dogra Raj [The Muslims of Kashmir and Dogra Raj], Achuton Ki Haalat-e-Zaar [The plight of the Untouchables], Bargazidah Rasul, Ghairon Mein Maqbul [The Chosen Prophet, Popular Among the Non-Muslims], Ta’surat-e-Qadian [The Impressions of Qadian].  

Mahasha Malik Fazl Hussain passed away on 18 September 1975, in Karachi, Pakistan. His funeral was brought to Rabwah on 19 September, and the next day, his funeral prayer was led by Hazrat Maulana Abul Ata Jalandhari. He was buried in Bahishti Maqbarah.