The sin war - Richard A. Knaak

When missionaries come to speak to the people of Kehjan-a once-united but now splintered city in the eastern part of the world-many listen, but little is understood other than the fact that angels and demons vie to steer the course of human destiny. However, one person who has no use for either side is Uldyssian, son of Diomedes. He questions the significance of either sect in the lives of common folk. Then, both missionaries are brutally slain, and the evidence points to Uldyssian, who is about to learn he himself has a destiny far beyond anything he ever imagined.