Quest to change dietyFollow

No quests, but you can buy a potion in the /marketplace with Station Cash to change your race and deity to any that are available to a particular race / class combination. It also doesn't change factions you've earned over the years, but will adjust the base factions due to race and/or diety due to the change.

http://forums.station.sony.com/eqold/posts/list.m?topic_id=156888 Old forums thread about it, when it became available.

Yther Ore.