This is the story of Maddix, an ex- Navy Seal turned pastor, who on a mission to search for terrorists, steps on a landmine and loses his leg. While his buddies work to stop the bleeding, he has an encounter with an angel who tell him that God has chosen him to battle demons. And so begins his story. It's all about spiritual warfare and definitely falls into the Christian fiction category.
It's not badly written and it has plenty of action. My only complaint is that the battle scenes seemed too long for my taste. It's also part of a series which I will probably continue, but at a later date.