F S Coplestone
This is a really helpful updated and expanded edition of the book that compares the teaching of the Bible with that of the Koran on key issues of faith. It is a wonderful aid to understanding what Muslims believe about God, Christ, the Bible, personal salvation, and other essential areas.
It is thorough yet written in easy-to-understand language.
Every Christian should have a copy for themselves, and one to give to a Muslim friend or acquaintance.