The Left Hand of God

A novel by Paul Hoffman, released in 2010. Raised by the zealous and militant Redeemers, Thomas Cale has been subjected to a life of brutal hardships and Training From Hell. When he finally gets an opportunity to escape, he flees to the city of Memphis, where he must survive political intrigue and the rigours of a new life. However, the Redeemers are unnaturally interested in getting him back. And their purpose might spell doom for the whole world...

Some say he will destroy the world. Maybe he will...

The story continues in a sequel, The Last Four Things.

This book shows examples of:

After the End: If this were set in our world, this is seemingly the only possible explanation for the similarities between our world and the one that Thomas Cale lives in. The world has seemingly regressed to a medieval / renaissance level of technology and society. That said, there isn't any explicit evidence for why the world is the way it is, or that it isn't just a completely alternative world in some ways parallel to ours.
Anti Christ: Redeemer Bosco believes Cale to be an Inversion of this: sent in to bring about the end of the world, but by God, not the devil.
As the Good Book Says...: The characters quote their own version of the Bible.
Cool Sword: The Edge. Unusually, only appears to get broken.
Crystal Dragon Jesus: The Redeemers are blatantly like Christianity while obviously not the same religion, the subtlety of which analogy is perfectly captured by the fact that their object of worship is a Son of God who was hanged. The briefly touched details of their schism with the Antagonists makes it further clear that the Redeemers correspond to Roman Catholicism and the Antagonists to Protestantism. The Redeemers are also a distillation and exaggeration of everything that was ever wrong about the church. A Jesus of Nazareth is actually mentioned in the novel, but the most we hear is that someone at least thinks he played the role of Jonah in the story about being swallowed by a fish.
Fantasy Counterpart Culture: Besides of the Crystal Dragon Jesus thing, Hoffman throws in real world names of peoples and places without any particular logic. Cultures may be inspired by elements of ones in the real world without adhering to them too closely, whereas in some cases he just flat out puts in some "Jews" who sound to be in about the same situation as they would have been in the real world at a similar historical era.
Low Fantasy: So low it's not even certain there is anything fantastic in the whole book. Only a couple of things suggest it -- the sweet-smelling substance recovered from inside a tortured young woman's body doesn't seem like a natural thing, and Kitty the Hare appears to be not exactly human. Of course, if Cale's mentor is right about him, that's certainly a fantasy element.