This book deals with the question of how evil and God can coexist--a question that is sometimes referred to as "the theodicy problem." The basic question goes: If God is all good and all-powerful, how can evil exist? One common answer is that evil doesn't really exist, but only appears to exist because we limited humans have inadequate information about, and can't take the long view of, God's plans; we only see part of the picture. I think this is a weak solution, which one can believe only by seriously twisting one's mind; it is pollyannaism, writ large and projected onto the entire universe. I believe that such a position is psychologically destructive, because it forces one to abdicate moral judgement and to deny and repress one's immediate moral responses to such obvious evils as the beating and sexual abuse of children and the torture or mass murder of innocents. The author, Rabbi Kushner, deserves credit for not adopting this very easy and mind-distorting "solution" to the theodicy problem.
Instead, Kushner posits that evil exists because God, while good, is not all-powerful. Kushner says that God wants the good, and assists in its achievement, but He is unable to be fully effective because His power is limited. This view has a certain plausibility to it and is logically consistent. It also may be reassuring to those who want to believe in a good God, but without twisting their mind into denying the existence of evil. By offering this honest solution to the theodicy problem, I believe Kushner will provide a way for some people to avoid the mind-distorting and psychologically damaging attempt to deny the existence evil.
Still, I think Kushner's solution is a cop out. I believe it is attractive to people only to the extent that they are unable or unwilling to seriously contemplate the possibility that there either (a) is no God or (b) is a God but He is so weak as to be insignificant to human life. I believe that an honest examination of world history--which really has been an endless sea of blood and pain from time immemorial--demonstrates that if there is any divine force for good at play, it is close to impotent. That is, I just don't think Kushner's view stands up to the facts of existence and history, which has consisted of endless waves of mass murder and vast suffering. I think the more honest solution to the theodicy problem is that God--as anything remotely resembling the traditional conception of a just force that intervenes in human life--simply does not exist.
Even if Kushner's view is wrong, might it still be beneficial? That is, might Kushner's view be a supportive and reassuring fiction? Perhaps it will serve this function for some, as the many positive customer comments below seem to suggest. But I believe the more important result is that it deflects attention from the real issues, and keeps people from digging deeper or seeking more adequate, honest solutions to their problems.
Evil is of two types: that arising from the natural world (natural disasters, disease, wild animals, etc.), and that inflicted by humans. For those concerned with suffering caused by the natural world, I think the best response is to recognize that such "evil" arises from an indifferent physical world, and that we can work to prevent or ameliorate such suffering in the future by striving to better understand the natural laws that govern the world, and to apply what knowledge we already have.
As for those who are concerned about evil caused by human beings, both in the world at large and in their own lives, a more helpful and honest author is Alice Miller. Her books, all sold through amazon, include Drama of the Gifted Child, For Your Own Good, Banished Knowledge, Breaking Down the Walls of Silence, and The Untouched Key. I believe that Miller's work provides a fairly complete understanding of the origins of evil inflicted by humans--everything from child abuse to mass murder.
Someone faced by a personal crisis, who feels they need the support of a more-or-less traditional religious faith, might gain from reading Rabbi Kushner's book. It's a fast, easy read, and may give one the boost one's looking for. But for those who are willing to devote the time and effort required to grapple with serious ideas, I believe Miller's unflinchingly honest books will prove more satisfying and useful.