Is it possible to be human without being spiritual? The mind does many things. It tells your body to breath, your heart to beat, your legs to move as you walk down the street often with out a conscious thought. But we do have thoughts that come through as a voice, in a language that we understand, and we listen and react with an action or as if we are in a conversation.
Well there is the proof. When we have thoughts that come to us as a voice... Who is listening? Who is speaking?Why must it be in a language that we understand? Why must it have that vocal quality or be in a language at all?
We use language to speak in a physical reality where there are other individuals seemingly separated from our own identity. So if this is all happening within the local region of the brain, why the language and the decision to react or not? It is because our identity of self expands beyond the visceral reality of our physical lives. We are all spiritual whether we accept it or not. We have a relationship between our physical identity and our non-local identity. They literally communicate and work together to not just navigate but to discover meaning, purpose, and to learn. This is the experience of being human and it is defined by our spirits relating to our senses. Every single one of us is spiritual.