It's a fantasy novel with a yellowish / whitish cover. The title was white or shiny. I believe there was a man on a horse on the cover. I first read it about 12 years ago. It's a fairly thick book.
In it, Gods exist alongside humans and rule over them. They can see everything a human is doing at all times unless the person is touching a man-made material like metal. I think they also want to rebel against the gods. I believe remembering the author and main characters to be male. At one point, I think they travel to another city which is rule by a different god.