The world was created by The Creator also called the Architect of Creation. In this he was aided by lesser beings who, by his grace, could tap into the source of creation. In the end, some of his agents desired Creation for themselves and rebelled. They were cast from the heights of Creation to its lowest depths.
From there the Fallen, as they were called, whispered in the ears of the Architect’s greatest creation, man. Man could tap the source of creation not by the grace of the Architect for he had given them a piece of it as their birthright. Yet man, tempted by the Fallen, often came to desire more of that power and thus was Creation corrupted by man’s desires beyond his abilities.
The Creator gave a promise that when certain signs were fulfilled those who were worthy would be called to him and together they would create and enjoy a new and better Creation. The worthy would be separated from the unworthy in a final conflict with the Fallen.
Yet somehow man conspired with the Fallen to bring the final conflict before the signs were fulfilled. In one dark night the Fallen were released upon Creation. As they tore at Creation men fought them and other men, leaving the world scarred and blasted. Yet, in the end the Fallen remained unopposed by, at least as far as man could see, by the Architect. As such they appeared poised to rule the world. This is the Harrowing.
Yet the Fallen did not stay within the world as its rulers. They retreated to their depths and although the Hierarchy of the Throne and the Cults of the Thousand Saints agree they are more present in the world than before they do not rule it. Yet man can still touch the source of creation and priests may still call upon the power of the Architect and his Saints within the world.
What happened that they do not rule the world? Some claimed the Fallen overthrew him and either killed him or drove him from Creation only to find they had no desire to rule. Others claimed that the promise was fulfilled and those who remained, both among man and the Fallen, have been abandoned in the old Creation which is beginning to decay away. The later point to the coming of Demons as proof that the world is ending. Those of the first theory counter Demons have gained their purchase because the Fallen (also called Devils) have refused to rule and thus maintain Creation.
And what does man do in this age? He does as he always has: lives, loves, fights, seeks treasure, strives to do good, and often does evil. Plus ça change, plus c’est la même chose