In this enlightening book Abu Hamid al-Ghazali explains the inner and outer secrets of the various actions of worship performed by Muslims. He explains the actions involved in the external elements of worship and outlines which of these actions are obligatory and which are sunna. He then discusses the inner requirements of the worship - the practice of the heart - and presents practical solutions for a distracted heart. This easy-to-read yet comprehensive work covers a range of topics from the essential outer aspects of how to worship, to the inner aspects of the state of the heart during worship and how to humble oneself completely. Being a practical yet profound book, this book is an essential reading for Muslims seeking a deeper understanding of worship and for anyone interested in understanding the meaning and place of worship in Islam.