A worthwhile investment. The layout of the book (split in to two parts for children under & over 6) is a great idea too. I've read it a few times with my 4 & 6 year old and they ask for more. It's even helpful as an adult to use the information to answer tricky question I've been asked too.
My son, who is 9 took up the book and read it before I had a chance to sit and read with him. He told me that the book is good. It answered a lot of questions he had which were unanswered.I will be bringing this book on a mission trip to read with the kids we serve.