Soulkeeper (The Keepers, 1)

When ancient magic suddenly returns to his land, a warrior priest must answer the call and protect his world from monsters that were once only legend in the first book of USA Today bestseller David Dalglish's epic fantasy trilogy.
Devin Eveson is a Soulkeeper, traveling through remote villages as a preacher and healer. But when a mysterious black water washes over the world, the veil is torn, flooding the land with ancient magic and forgotten races: fire that dances as if alive, corpses that walk, and creatures that can manipulate time itself. And not all the creatures that have re-awakened remember humanity fondly.
As the land grows more dangerous and more chaotic, Soulkeepers are turning up dead, their bodies transformed into macabre works of art. Devin must set aside his words of peace and accept his new role: slayer of monsters and protector of the human race.

For more from David Dalglish, check out:

Shadowdance
A Dance of Cloaks
A Dance of Blades
A Dance of Mirrors
A Dance of Shadows
A Dance of Ghosts
A Dance of Chaos
Seraphim
Skyborn
Fireborn
Shadowborn