At a particularly rough point in a novel that is particularly rough and dark all around, the main character thinks to herself, "No one wanted a hero who couldn't save herself." I have to say, for much of the novel I tended towards agreeing with that sentiment. The aforementioned main character, Nyx, is by turns alcoholic, drug-addicted, suicidal, and sheer bloody-mindedly contrary to the point of inviting injury. Even her erstwhile, never-quite romantic interest is flatly and repeatedly stated to be ineffective at best and useless at worst in his role on her team. But that said: Nyx also comes out with snappy responses like:
a captor: "You're just an educated bloodletter. What do you know about God's plan, about the salvation of your soul?"
Nyx: "No more than a butcher...but a butcher knows how to serve it halal."
And as you can probably tell from that, it's not just quick wit that God's War has going for it. There's also an incredibly original setting that draws on religion a great deal - mainly Islam, obviously - to create a world and conflict of cultures that will be alien to most readers, without any aliens at all. And then there's the bugs. Insects of all stripes feature prominently throughout, so if you're squeamish at all in that regard, you might want to get your scifi elsewhere.
In any case, I was continuously hungry to know more of the setting. The plot required all of my attention to follow, however, in being rife with double-crosses, politics, and unpredictable violence. In that, though, my frustration with the characters started to turn when I struggled along with Nyx to follow a particularly complex betrayal: as much as this is on one level a science fiction story about a religious war, it's more a noir story dropped into that setting, with a tough-as-nails bounty hunter instead of a sullen detective as lead. Once I realized the fullness of that, I began to savor the darkness and desperation of Nyx and her world, and realized that any glimmer of brightness that I'd despaired at not finding wasn't missing per se, but rather had to be so bittersweet and tough that it could barely be recognized. Give God's War a try with that in mind, and you won't be disappointed.