It's been awhile, but one thing I remember is his point about God sometimes not feeling "present" when we pray - it's because *we* are not prepared to be in God's presence. God is having mercy on us.
Marvelous book. One of my favorites. I'm going to go out a bit on a limb here, but that book convinced me that Anthony Bloom was a saint. I don't know if he'll ever be canonized, but his story combined with the wisdom on prayer in the book itself... beautiful.