On which subject, Corrie Ten Boom's "The Hiding Place" is one of my favourite Christian books. "Every Christian should read this" is an over-used description. But it'd definitely be one of my "Desert Island" books. I've read it to my children twice (with a little bit of age-related censorship at some of the more gruesome points).
There are two companion books covering other parts of her astonishing life, "In my Father's House", and "Tramp for the Lord", which are also highly worth reading. (The latter is rather disjointed. But it has a lot of spiritual profit in in, so we should not be churlish!).