Rebecca Nye is a bit of an expert in children's spirituality: she co-wrote "Spirit of the Child", which is about as academic as this sort of thing gets. This new work isn't a book for academics but a book for practitioners: anyone who ever ends up leading Sunday School for example.
Nye takes the insights from her academic work into children's spirituality and places them against actual practice in our churches (mainly UK-based, but relevant elsewhere.) With this, she has an alarming thesis. Even seemingly child-friendly churches are not friendly to children's spirituality: in fact, they may even alienate children in the long run.
If she's right, then the long term reason behind church attendance falling away is that generations of children have been inoculated against it by Sunday School that bypasses their spirituality. She quotes the situation where the Sunday school teacher says: "What's small, with long teeth and a fluffy tail?" and the child says, "Well, it sounds like a squirrel, but I know the answer must be Jesus."
In creating Q&A sessions, with 'right' answers, then we've inhibited children's spirituality.
Or again, too often Sunday school activities can be reduced to: "now finish painting the whale, add on the paper in the collage and stick it together and you've got to do it in 2 minutes before you show it to congregation". This creates a seeming sympathy with children but isn't actually answering them on their level, or dealing with THEIR questions.
The book is in short chapters, often with questions at the end, some of which I've used in a workshop with teachers at the Sunday school I run, and we've found it incredibly useful, albeit challenging.
To follow through on her approach is seriously intensive.
For example, she wonders why lots of time is spent on the visual look of the main Church while children often get stuck in a side room without any thought to visual layout. Yes, that's right. But then, churches are imperfect buildings and it's rare that there is a very good 2nd space which works perfectly for Sunday School or whatever.
Also, her expectation of leaders is very high: for her, children's leaders need to be able to interpret children's nascent spiritual answers and gently tease more out of that which is already innate within them. She may be right, but to be honest, I'm glad when my volunteers just show up on time!
Still, a brilliant book. Easy to read and seriously challenging. If people follow through on it, it will change the Church as we know it.