I read this very interesting book at the recommendation of my sister-in-law. Everyone knows about WWII, but this is the first time I've ever considered domestic life in occupied Europe. The book has a lot of evil in it, but she doesn't go into many graphic details of the violence around her. (PG-13, suitable for a middle-schooler who is comfortable with the subject matter.)
To me the primary theme was Acts 5:29--we must obey God rather than men. It some situations it is impossible to avoid breaking a commandment. The characters struggle with this--especieally those who think they're fairly righteous.
The book has religious overtones. Corrie and her sister come to identify their sufferings with Christ's. The Ten Booms are devout Reformed Christians, but her book is not sectarian. In fact, while worshiping with other women in the concentration camp toward the end of the book, Corrie says she knows "that in darkness God's truth shines most clear." The truth the prisoners are seeing, despite different denominational traditions, is that we all come to God empty-handed and weak, and our only hope is for His mercy because of Jesus.
