This answer comes from the chapter, Consciousness and Non-Physical Existence, in the book, In Secret Diffusion: The Upper Realm Answers Questions About Earth, by Linda J. Brown:
Is there such a thing as a non-physical existence?
The Holy Spirit: “No, there isn’t. All realms appear physical to those who are in them. They appear non-physical to those realms below them, but physical to those above them. This has to do with the placement of molecules and the distance between them. To a lower level, the upper level’s molecules appear so far spread that they do not seem connected. This is simply a physics approach to matter, which becomes more tightly-compacted as size is reduced.
This is why the other planets in your solar system appear, to Earth humans, to be so hostile and uninhabitable. It is because life exists at a higher vibration there and the molecules of their reality give certain erroneous impressions to your space travelers or probes.
In reality, those planet’s surfaces do not appear to Us as they do to you and We live all over the solar system. We are in a different dimension from those on your planet. This also applies to Us when We approach the planets of higher dimensions than Ourselves. What appears to be inhospitable and empty of life is actually filled with those living in another dimension than your own.”