Upsides of this book include explanations of terms and a voluminous use of the Q'uran, Surats and Hadiths. The primary downside is that this book is not intended to be explanatory, but instead apologetic. The author takes many opportunities to take shots at Jews and Christians as groups. When attacking Christian perspectives, he uses whatever strain of Christianity is most useful, from liberal-critical to fundamentalist, to make his point seem valid. Furthermore, he completely dismisses the militant aspect of Islam today, acting as if it is some minor aberration and giving the reader no clue why that strain is as popular as it is. If you want a single volume on Islam, this isn't it.