Multi-Dimensionalism is fascinating and incomprehensible. One of those things of which words can only serve as sign posts to the true reality. I believe our consciousness can access and live in other dimensions than the one we usually operate in physically. I believe that the “spirit world” exists in these other dimensions. Sometimes the other dimensions reveal themselves when we drop our paradigms and programming of how our reality “should” be.
I think other dimensions are analogous to our different levels of consciousness. Where normal consciousness is the three dimensional physical reality. Subconscious is a dimension deeper. And unconscious is a dimension even deeper. I believe that dimensions are not black and white. I think there is a spectrum. Dimensions do not have hard edges.