How do I know that most of our being exists outside the system? From my own experiences, and I'm far from the only one who knows this. The whole thing is vast; actually, there is not a "whole thing" because it is continually unfolding. It doesn't fit into a box.
I don't "believe" that we exist outside this system as well as in it (when we have a body). I know. "Belief" is a word we use when we don't know whether something is true or not but we figure or prefer to accept that it is.
The stream of attention that goes into experiencing physical reality through a body is a trickle of what we are. Yet it's important that this stream remain a trickle in order to fully experience this reality. To appreciate the physical world and learn about it demands a narrow focus. This trickle of what we are needs to really concentrate to learn the rules of this reality, the physics of it, how to maneuver within it, how to survive in it. Another way to put it is how to keep body and "soul" together.
Once we have learned how to negotiate this reality, it's natural to branch out, to play with our focus of awareness, to learn to shift it into other realities. However, what we do here depends on many factors. Some of us came here precisely for the conditions this reality offers and shifting our attention would hamper our purposes. Others of us came here to bring more of the greater reality into play. To find our way, we must look first to our inner guide and teacher, our own inner being that knows who we are and why we have a body in this reality at this time.
There are systems for achieving enlightenment, psychic development, consciousness expansion, and so forth. A person who is attracted to one or more of these systems is impelled to do so by their own inner connection with the parts of themselves that are outside of this system. Every system needs new energy, new ideas, new possibilities, if it is not to die on the vine.
Some people are totally uninterested in expanding their consciousness either because they are focused on something specific they streamed into this reality to do, or they have gotten trapped into thinking that all they are is their body. The difference between those on a mission and those who are trapped is that the former will largely be passionate about their lives and the latter will be fearful.
Suffering is the main driver of the desire to broaden one's stream of awareness. Suffering is a symptom of being trapped in tunnel vision. When we suffer, we seek a way out. When we're hungry, we seek food.
The greatest happiness is being centered in connection with greater being. I don't call it "my" greater being because it is a part of many streams of consciousness that can be braided into many different configurations. I know myself to be both inside and outside of this system and open to endless discovery and creativity. This world we call the physical world is a marvel of color, form, texture, fragrance, sound, and unfolding variety. Sure, it is slow moving, but that is part of its beauty. Things take time here. Time is a fascinating medium for constructing things that wouldn't exist without it. I used to rail at the density of matter in this reality and how hard it could make life be, but at some point I began to admire its solidity and not see it as impediment.
We cannot judge another's development or what they should do. I used to think everybody needed to expand their minds, but I've learned that's not true. A certain scientist, musician, artist, or anyone deeply engaged in life, may be on a definite mission of learning or doing or accomplishing and has intentionally has blocked any side trips. A person might be focused on parenting or learning compassion or studying the mechanics of lifeforms in this medium and intentionally block out other data that would be distracting.
Even so, we all use our inner ways of sensing even if we don't always become aware of it. We all sometimes see around the corners and edges of things and experience "anomalies" that don't fit. The main thing is to be aware of when we feel moved to expand and when we are happily engaged in our focus here. When we are uncomfortable, when we feel that something's missing, when we can't know fulfillment, it's time to engage our inner teacher.
Our inner teacher, as I call is, is us outside of the system. It can see what we, with our tunnel vision, cannot. Standing outside the system, it can see the bigger picture and give us more data, new ideas, and inspiration. We are not trapped here.
Are there guides and teachers and beings outside of our personal stream of awareness that we can communicate with as well as with our "inner teacher"? Why wouldn't there be, unless we or you or I were the only stream of life, of consciousness, existing? What I experience is that the me I know as a human is like a tiny trickle of vast oceans. Yet I don't feel small because I am a part of the great confluence of life, being, or consciousness, however you want to term it. And as a molecule in the ocean, I have access to its vastness and can play in its depths or rides the waves on the surface.