Only heat will remain. And the heat will dissipate. They are lying. The world of spirits is a place of great changes. And change is entropy.
Spirits are beings from outside of the world.
They cannot exist without it, feeding of its entropy as we do. At the moment of dying. It will see beyond the illusions of its existence and pass into a new existence. Unfortunately almost all choose to forget that moment. It is our task to awaken those who are ready, and make others ready.