The Electric Church is a 2007 science fiction book by Jeff Somers. First in a series I'd somehow never heard of, I can see many happy hours of reading ahead as I pick up the others. You can read an excerpt here.
from the back of the book:
Avery Cates is a very bad man. Some might call him a criminal. He might even be a killer —for the Right Price. But right now, Avery Cates is scared. He's up against the Monks: cyborgs with human brains, enhanced robotic bodies, and a small arsenal of advanced weaponry. Their mission is to convert anyone and everyone to the Electric Church. But there is just one snag: Conversion means death.SF Signal has a glowing review and calls it "A first-rate piece of science fiction entertainment." The SF Site review says, "Somers writes with assurance and style. This is fun, cyberpunky noir SF with just the right mix of fatalism and attitude, seasoned with plenty of bullets and black comedy." SF Revu highly recommends it saying, "The entire effort is well done and an excellent melding of form and style."