Our true nature is something that is ineffable. In other words, it's not something you can grasp, it's not something you can really think about, it's not something you can touch, taste, or feel. (...) Because it has no shape, because it has no form, that is the reason that I call it spirit. Spirit is that which exists, but it doesn't have a particular shape or a particular form.

The Basic Teachings - Part 1: Principles of the Teaching (2009)