This was the first Hans Kung book that I have read, and I must say, I am rather impressed with his level of scholarship, clarity of thought, and vast scope of learning. His treatment of the interaction of science and theology was not bad, though I must confess that I did not think he was quite as good at it as Polkinghorne. However, I found that I was very dissapointed with many of the conclusions that Kung reached. In the majority of issues he discusses, he ends up reconsiling science and Christianity by having Christianity give up any claims it has in any area that science touches. Now, I am not advocating a literal six-day creation, or suggesting that we believe that the earth is flat, but I do think he has gone a bit far in denying that miracles happen. Whenever he perceives that Christianity and science can even potentially come into conflict, he always decides that (what he understands to be) science wins.
For example, Scripture claims that Jesus performed miracles. Science tells us (according to Kung) that miracles cannot happen. What should we conclude? Well, according to Kung, we should conclude that the miracles did not happen. You would think that this would effectively undermine Christianity, but Kung tries to defend this position by making the absurd claim that the miracle stories in both the Old and New Testaments were not meant by the authors to be taken literally. It may be that Kung does not take them literally, but it is absolutely absurd to claim that the persons who wrote them, and the persons who originally recieved them, did not think they were to be taken literally. I found his section on miracles (pg. 151ff.) to be absolutely appalling, not because of his denial of miracles (though I do disagree with that), but because he actually tried to claim that this denial was in line with the thinking of the ancient people's who wrote and received the Scriptures. He could at least be honest and face up to the fact that his understanding of the historicity of Scripture is not the same as that of the authors of Scripture.
Further, in his effort to avoid conflict, he banishes Christianity to the sphere of personal preference. He explicitly says that "no religion can dispute with others their way to salvation. Rather it is important in recognition of human freedom, especially the real freedom of faith, for each to respect its own path of faith" (p. 197). Christian teaching is no longer objectively true, but is instead a subjective understanding of the "other," which can neither come into conflict with science and history nor even competing (and logically incompatible) religions. I think his approach to the topic is well summed up in his conclusions about the resurrection, which is central to Christianity. He says that "I do not believe in the later legendary elaborations of the New Testament message of the resurrection but in its original core: that this Jesus of Nazareth did not die into nothingness, but into God" (p. 205).
In short, Kung has a lot of good things to say about the compatibility of science and theism in general. He does a very good job of showing that science has not been, nor can ever be, the cause of the death of God. However, his sections of the relationship of science and Christianity are relatively useless for someone who holds to orthodox Christianity, as he promotes harmony by demolishing the claims of Christianity so that they cannot oppose what he understands to be science. I am emphaticly NOT saying that we should use Scripture as a science textbook, but I think denying both miracles and the historicity of the gospels amounts to denying the truthfulness of anything resembling historical Christianity.
It may seem that I have had little good to say about a book I gave four stars. Let me emphasize that a good portion of this book is actually quite helpful. Those parts have already been written about in the previous reviews here. I simply wished to focus on the parts which previous reviewers have not. This is not a terrible book, as long as you understand what understanding of Christianity Kung is bringing to the table with him. If you disagree (as I do) with his liberal Christianity, then parts of it (the parts which I have mentioned) will be relatively useless and probably aggrivating to you, but there is still a significant amount of good, well thought out work to be had in it.
Overall grade: B.