The Aga Khan used to raise his voice in the defence of Islam, whenever it was under inroad. In October, 1951, the "London Times" made some unfair allegations against Islam and the Prophet Muhammad. In a spirited reply to the "London Times" on October 22, 1951, he said that, "Islam was not only tolerant of other faiths but most respectful and indeed fully accepted the divine inspiration of all theistic faiths that came before Islam." He further said: "If there has been violent reaction against the West in some Muslim countries, the reason is to be found in the attitude and behaviour of the westerners, their ignorance and want of respect for the faith and culture of Islam, of which the reference to that faith in your leading article is a typical and usual example."
His illustrious and outstanding services for the cause of Islam were not confined to newspapers only. As a patron of Western Islamic Society, London, he worked for the educational and social uplift of the Muslims. He built and maintained many mosques, one of them is the Aga Khan Mosque at Cardiff. He had also given Rs. 75,000/- for the repairing of al-Aqsa Mosque, and Rs. 25,000/- for the Nairobi Mosque. He also established the Aga Khan Construction Fund to repair Badshahi Mosque in Lahore. In 1936, the Muslims of Sind had formed a committee led by Sir Ghulam Hussain Hidayatullah to erect a memorial for the services of the Aga Khan towards the creation of Sind province. It was decided to build a Grand Mosque and name it after the Aga Khan. When he was informed the plan, the Aga Khan agreed to contribute on rupee by rupee basis for the proposed mosque fund, but said: "Why name the mosque after me?" He prevailed upon the committee to name it as Muhammad Jamia Masjid. This clearly shows that he did not wish to bask in the sunshine of acclamation and praise. What he wanted was the greater glory of Islam.
Stating about the Aga Khan's uncontrollable love for Islam, Mushir Hosain Kidwai of Gadia quotes an event of an early twenties that: "When a deputation from India consisting of His Highness the Aga Khan, late Messrs. Chotani and Hasan Imam was selected by the Government of India, and later on Dr. Ansari, and on the most particular insistence of His Highness himself, I was also included in it by Mr. Montague, on our arrival in England, to plead for the return of Thrace and Syrna to Turkey before the British Cabinet. After our spokesman, Mr. Hasan Imam, had put the case, the Prime Minister, Mr. Lloyd George, pertinently asked: "Now that the Greeks are in military possession of Thrace who will turn them out from there." Mr. Hasan Imam did not answer. He was in fact given no time to speak. None of us could speak. It was His Highness who enthusiastically jumped up and with a raised finger said: "Well, Mr. Prime Minister, old though I am, I will go sword in hand and turn them out. We will charter ships. We will do everything. Leave them to us." Mr. Lloyd George was thunderstuck. He could not give a reply except murmuring: "No, no, we cannot do that." My sensitive mind was greatly impressed by the words and the way the Aga Khan spoke. Every word cut deep into my heart. I remember every word upto this day. I confess I wished those words had come out of my mouth so spontaneously as they did from that of His Highness. They revealed the love, sincere and intense love for Islam with which the heart of the man who spoke out his mind. It was wonderful. For that remark he was a true Muslim overpowered by the love of Islam. He was nothing else. The blood of the Prophet in his veins made him speak out those words. They indicated that he was ready, sincerely ready to give up his wealth, his position, his very life, for Islam - yes for Islam, not particularly for that sect or school of which His Highness personally was the highest head."
The above few instances are only a few drops in the splendid stream with which the Aga Khan III has watered the garden of Islam. Ever green leaves, fragrant flowers and sweetest fruits have come into existence, and Muslim world, while thanking this great champion of Islam shall never forget his noble and outstanding contributions.
During his long Imamate period, the Aga Khan III devoted much of his time and resources in consolidating and organizing the Ismaili community, especially in India and East Africa. He was notably concerned with introducing the socio-economic reforms, transforming his followers into a modern, self-sufficient community with high standard of education and welfare. The development of a new communal organisation thus, became one of the Aga Khan's major tasks.
In 1956, Queen Elizabeth of Britain conferred upon the Aga Khan the title of Grand Cross of the Saint Michael and Saint George (G.C.M.G.).