A co-worker lent me this one, and because I wanted to know more about what she found challenging, I read it. I would have quit after the first chapter had it not been for that fact. Crabb's idea isn't new, and he spends over 120 pages harping on a single (and easy to grasp, in my opinion) idea. Then, just when I thought he might have some true insight, he pops out yet another formula on how to get close to God. How very disappointing!
I can see how this book might resonate with the "Martha" types out there--those who are constantly doing, constantly striving, who are in the kitchen washing dishes while Mary is sitting at Jesus' feet. My co-worker (very much a Martha, and Type A to the hilt) fits this, so I'm not surprised that it challenged her. For me, very much a Mary, I knew a long time ago that being a child of God did not mean that God was a vending machine I could push buttons on, nor is there anything I could ever DO to gain blessings. Because of who I am, and because of the journey I've been on, this book had very little to say.
If you are a Type A Martha, go ahead and read it--it might help you break out of your deeds-focused mind-set. Otherwise, I'd skip this one.