This book is important because it is:

Unique. Heaven on Earth offers a critique of extremism that is human rights-based and entertaining - combining the comparative approach of Karen Armstrong and the immediacy of Ed Husain (The Islamist) with storytelling.
Timely. At a time of veil bans, Qur'an burnings and English Defence League protests, Kadri voices a liberal view of Islamic history and shows Muslims working against repression. This book explains up-to-the-minute brutalities.
Epic. Interviews, anecdotes, personal reflection and analysis are set against a narrative that sweeps from seventh-century Mecca to the war in Afghanistan. Civilisations are evoked via the vivid lives of caliphs, mystics, and travellers. Legal changes are described through the feuds, courtroom dramas, conquests and cataclysms that have left their mark on modern Islamic law.
First-hand. On the road for five months, Kadri travelled through Iran just before the June 2009 election protests, and took part in a human rights conference there with ayatollahs and academics.
Eye-opening. This book goes beyond the explosive headline issues (criminal justice, women, jihad, religious freedom) to reveal the stranger ones: genie exorcisms; the legal consequences of premature ejaculation; online fatwa advice; the sharia approach to Facebook and Qur'anic mobile phone ringtones, etc.
Bold. Heaven on Earth primarily targets religious extremism, but also cuts anti-Muslim panic down to size.