Toynbee rehashes some material from his multi-volume work, but there are still some great chapters here. I especially liked 'The Re-Erection of Two Graeco-Roman Idols,' and 'Idolization of the Technician,' and most especially his look at what happens between religions and empires. Also valuable is how Toynbee points out that the way religion and society interact goes far beyond whatever individuals do on 'Sunday' (I use the term broadly). I found his comments about power and suffering provoking.
The book's significant problems come when Toynbee goes beyond looking at religion as an historian, and starts looking at religion per se. He seems too much of a Platonist. As he does not believe in the Incarnation, he seems to posit too great a difference between the physical/spiritual, animal/rational, etc. Thus, religious truths get boiled down to their 'essence' apart from their 'incarnations,' which in Toynbee's eyes inevitably distort 'true' religion. Religious 'truth' gets buried too deep in the sub-conscious or to put too high in the ethereal mist. If we think of Raphael's famous painting of the Academy in Athens (and imagine adding Carl Jung pointing back at himself, beside Plato and Aristotle,) why couldn't all three be right? Can't truth be 'out there, in front of us, and within us (to some extent anyway). Toynbee, I think, would exclude Aristotle, or at least diminish his role, and this error impacts his thinking.