I had high hopes for this book, but was largely disappointed. I guess I had hoped that Miller would take us into the Celtic mindset in prayer, but found instead that he extracted some nuggets from the Celtic mindset to try to present them to the American Evangelical--as a way of deepening shallow prayer.
So, it did have substance. Miller works through six types of prayer: Trinity prayer, scripture prayer, long wandering prayer, nature prayer, lorica prayer (prayer for protection, based on St. Patricks' breastplate [or lorica]), and confessional prayer. The last two were the most interesting, and the best rooted in the Celtic tradition (although with confessional prayer, he drew equally on Augustine). I felt like finally the book might be getting somewhere.
There were lots of good moments and insights in this book, but it could easily have been only half as long and lost virtually nothing.