Where Gather the Gods: Book I of The Walking Gods Trilogy. The Walking Gods Trilogy, #1

A chance encounter with armored figures brings Itidal out of the desert. For thousands of years, perhaps longer, he has tromped across the pale sands, but now he is drawn to civilization in a world where civilization should not exist. To him, men are little more than savage beasts, occasionally gathering into small villages though little more. Now Itidal learns of a city, and he strides forward to investigate.
What he finds are buildings and bankers, soldiers and slaves, peasants and priests. It is all young, only centuries old, new to mankind, but it is indeed civilization, a civilization with a jealous god. The high priest himself is curious and always questing for power, willing to make any sacrifice to learn the secrets of the ancients, but his god holds back knowledge, only giving out what is deemed necessary.
These yearnings cannot go unchallenged forever, however, and soon enough another god makes his presence known, a hungry god with unfathomable appetites. Between these gods and the high priest is where Itidal finds himself. Disgusted at the rise of civilization, holding no true love for the other gods, Itidal forges a tenuous alliance with the high priest, but other gods are out there somewhere, perhaps watching and waiting, for a time of gathering is at hand.