"Today the Muslim world is no longer somewhere else." In fact, a number of different religious viewpoints are likely represented in your backyard, and for that reason, it is important for Christians to acquaint themselves with worldviews different than their own.
This is an excellent book for that purpose. Derek Cooper provides general overviews of Hinduism, Buddhism, Judaism, Confucianism, and Islam, and then offers explanations of the different Christian theological responses -- inclusivism, exclusivism, pluralism, universalism, and particularism.
Of these views, particularism (p. 164f) is the most recent and least known. It is the view that since each religion has its own particular goal or aim, it is inappropriate to apply the Christian view of salvation to them. Buddhists, for instance, might reach nirvana, but they will not find "salvation" as Christians understand it, because that's not what Buddhists pursue.
The advantage of this perspective is that it honors the distinctives of each religion. Ironically, pluralists dishonor world religions by suggesting they are in essence all the same. A Muslim, for instance, does not want to be told that his religion is basically the same as Judaism. The problem with particularism, however, is that it suggests that ultimate reality (the divine) is dependent upon what people make it. It's hard to conceive how mutually exclusive views of God can all simultaneously be true.
For some this book might seem too general, but that's what makes it such a good introduction to the topic. Cooper is definitely writing from a Christian perspective, but he is always fair and respectful to the religions he describes, which is an important lesson for all Christians to learn.