The world refers to material creation which is divided into: the World of Ethereal Matter and the World of Gross Matter. It is also referred to as Subsequent Creation because it arose subsequently as a copy of the real original creation, which is spiritual.
Human spirits arise from the spiritual creation but descend into the World for the purposes of maturing. They need this world for their development and as a training ground whereby also as a result they uplift this world to a higher state through the special talents that they have been endowed with.
In this way, this world would be exposed to the ever-quickening power of the spirit which would otherwise have been impossible, keeping it forever young, resembling the original creation in its beauty. This, the human spirits failed to do, hence the all-pervading ugliness.
The World is subject to the ever-recurring cycle of evolution and dissolution whereby the present form is destroyed and new forms arise through special combinations. Human spirits in the World of Matter would have to be so mature that they can return to Paradise on time and do not get caught up in these cataclysmic events, hence the urgency of spiritual teachings to make haste and adjust oneself to the Will of God.