Why study other religions? I think I will try to answer that question from a personal perspective. The question then becomes, how can it benefit me or how can it help me benefit others by knowing something about their religions.
If I am concerned about others, I will be interested in their lives. What problems do they have and how do they face them? Certainly religion plays a part in those things. How do I meet them? Should I assume that everyone is like me - that they have the same hope and dreams, that they see the world the same? It is often the case that people make these assumptions when they meet but it is evident that much confusion and misunderstanding would be prevented if instead, the assumptions held were that new acquainanced were discoveries to be made. Connection is made when I understand another person's point of view. I can connect on points of similarity but I can also connect on shared interest in differences.
If I want to be a benefit to others, I need to understand their world view. Some attempts to help an individual that hold different beliefs may actually be taboo in their religion. Can I be of any benefit to them if they reject me?
In a different vein, I am a Christian. I would not be a Christian if I did not think that Christianity held an accurate view of reality. Yet, on studying other religions, I find that they have different focuses on life and have come to more indepth understanding in some elements of life than I have found in my own system of beliefs. For instance, although Christianity has somewhat to say about materialism and self discipline, Buddhism has explored the issues in much more depth. The native religions of North America have much to say about what it is to live a balanced life. In an age of frantic extremes, balance is greatly needed. I find that other religious people have much of value to say.
And finally, and I think also relevant to this book, it is pleasant to sit back and read the tales of other people that give voice to their spirit as a people, their aspirations, their hopes and dreams.