Abstract: Imam al-Ghazali has been regarded as the mujaddid (the reviver or the Islamic reformer) of the 5th century AH of Islam, and has been credited with various titles, of which the most famous is as Hujjat al-Islam (Proof of Islam). This article investigates the development of al-Ghazali’s thought and spiritual journey through different stages of his life,ie Spiritual Illumination, Al-Ghazzali Praises Sufism, Becomes a Sufi, Sufism The One True Way. Ghazali’s Impact on Sufism .This article basesd how Al-Ghazali renounced his brilliant career and turned to Sufism and radically transformed to become a personal Sufi during the seclusion period, leading to his subsequently becoming an active public Sufi.and contributed in this field