The Revival of The Religious Sciences, Volume 1

Iḥyā′ ‘Ulūm al Dīn  ( transl.   The Revival of the Religious Knowledge ;  Arabic :  إحياء علوم الدين ‎) is an 11th-century book written by  Abū Ḥāmid Muḥammad ibn Muḥammad al-Ghazali .  The book was composed in  Arabic  and was based on personal religious experience. It is regarded as one of his chief works and a classic introduction to the pious muslim's way to God.  Originally spanning over 40 volumes, it deals with the principles and practices of Islam and demonstrates how these can be made the basis of a reflective religious life, thereby attaining the higher stages of Sufism. Some consider  Kimiyā-ye Sa'ādat  as a rewrite of this work, which is a common misconception. Kimyā-ye Sa'ādat is shorter than this, however Ghazali said that he wrote the former to reflect the nature of the latter and a few of his other theological writings.