Forbidden Magic (The Godwars, Book 1)

by Angus Wells

This is about a prince who was a younger son and was not in line for the throne and whose father decided he would become a priest when he wanted to be a scholar. Then he got a chance to go on a quest which was much more in line with what he wanted to do so he ran away from home to follow this quest only to find himself and more trouble than he wanted.