Book excerpt: An expert in the study of Islam answers thirty important questions about Muhammad, offering a clear and concise guide to his life and religious significance. This companion volume to the author's A Concise Guide to the Quran answers many of the key questions non-Muslims have about Muhammad, reveals the importance of Muhammad for Christian-Muslim and Jewish-Muslim interfaith relations, and examines Muslim and non-Muslim primary sources. This introductory guide is written for anyone with little to no knowledge of Islam who wants to learn about Muslims, their beliefs, and their prophet.