When we study the sacred books we must understand that all the words just appear to be words associated with our world. The words however represent spiritual objects and roots, which are under no circumstances connected to our world. There should be no confusion of these spiritual concepts and physical objects.
All the worlds, including our world and all the objects in them are in tune with the single thought of creation: to give endless pleasure to the creature – the soul. This single purpose envelops all creation, from the beginning to the end. It is this purpose that determines all the suffering that we go through, our internal work upon ourselves, and the reward. After the individual correction all the souls will re-unite into a single soul. The soul receives not just a double pleasure ( from both sensing the pleasure and from bringing pleasure to the Creator ), but this pleasure is also multiplied by the number of re-connected souls. Meanwhile, the more people are ascending spiritually by working internally on themselves, the more they start seeing true reality and sensing the other worlds. While still living in our world they are able to attain all the worlds.