Abstract
Al-Ghazali is considered as imam (the most prominent) in epistemological critique and religious sects during his time, and one of the most prominent in defending the belief of Ahl al-Sunnah wa al-Jama'ah (Sunni Muslims, Sunnis, Sunnites). He is also considered one of the most prominent of theorizing of the Ash'ari theology (Asharites or Ash'arism) and Sufi thought. He was able to purify philosophy from superstition, and clarifies what is bad from what is sound, and he is considered as mujaddid (reformer) in his time. He was also distinguished by his intelligence, quality of writing, and erudition, as the objectives of the research were the manifestation of al-Ghazali's approach in defending the Islamic faith and his opinion on philosophy, theology, mysticism, and al-Batiniyyah (The Sect of Batiniyya; esotericism) through studying his position in his book al-Iqtisad fi al-I'tiqad (The Moderation in Belief), Tahafut al-Falasifah (The Incoherence of the Philosophers), al-Munqidh min al-Dalal (The Rescuer from Error) and Fada'ih al-Batiniyyah (The Infamies of the Esotericists). His positions were studied according to the historical, inductive, analytical, and critical research method. The study found that al-Ghazali was able to be the master of his time in defending and establishing the belief of Ahl al-Sunnah wa al-Jama'ah, as he was also aware of the war to the al-Batiniyyah and scholars, sultans, and the common people were charged with its war. Likewise, al-Ghazali worked on establishing the Islamic faith and demonstrating it with textual and rational evidence. He criticized 'Ilm al-Kalam (Islamic scholastic theology) and aiming it in accordance with the Islamic faith, and its use in defending and defining the Islamic faith and called for it to be preserved from the common people and to be used only in defence of the Islamic faith.