"They turned their backs on the common people and, like the gods they worshipped, they were gone." — Lorekeeper Aeron
The followers of the Old Religion - which is not the official name, but this is what it is mainly referred to as nowadays - were obsessed with death. In their minds, the Gods give all and take all. Whenever someone died, it was presumed that the Gods have called them to their service. All funerals followed complicated rules and proceedings that had to be fulfilled to the letter exactly - based on that person's life, age, social caste and many other aspects, so the Gods would get the most out of the "sacrifice". This was the main job of many ancient priests as only the chosen ones were able to speak on the wishes of Gods and fulfill them. For that the priests have always enjoyed priviledged position among the society. The High Priests were the only one allowed to speak on the gifts from Gods and give out sermons in their name.
The profession turned obsolete when the common people rebelled against the old traditions and renounced the Old Gods and their rules. People refused to be controlled by them even in their death and demanded freedom. If you are an Icon Worshipper, you believe to be set free by them, humanity rescued. But for many others, the strict rules of the old religion were simply too rigid, so people started to seek the solace for their souls elsewhere. No matter which story you believe in, the old empires and kingdoms fell, the temples were abandoned, the rituals of old were forgotten. The history is not clear on why the religion fell out of favour, there were many periods of dark ages and most of the records about events were simply lost to nature.
Nowadays, the knowledge about the Old Gods and scriptures are considered nothing more than a rare and obscure hobby.
