I have to ask, because I'm stilling not understanding this, but why do you and other people believe that this experience (which, btw, what is it that you do to have this experience?) is of a God/gods/higher power? Yes, you all have experienced basically the same thing, but why is it that you've all more or less come to the conclusion that what you've experienced is in fact a God/gods/higher power? Why could it not be something else?
When you're happy, how do you know it's happiness and not something else? When you're angry, how do you know it's anger and not something else? I know this is going to be a bit unsatisfactory, but the truth is: you just know. It feels like coming home; It feels like nothing else.
But to break it down somewhat, we can analyze a common feature of the mystical experience. People report the sensation that existence is not composed of separate parts, but is a unified and connected Whole. It is in them, and they are in it, and nothing has ever been otherwise.
With that in mind, let's quickly examine the general trend of human growth. There are two really simple ways that you can summarize what happens as people develop. One is that we learn to take a greater number of perspectives. Another is to say that
mental growth is a process of expanding the boundary line between self and other, which I find to be more illuminating.
Many people identify only with certain parts of their conscious mind; they repress or deny certain unwanted or uncomfortable thoughts and desires. Psychotherapy allows people to re-own these repressed thoughts, moving the boundary from 'persona' to 'ego.'
Most people stop there, which is as good a place as any to stop, I suppose. At this point, one is identified with the conscious mind and the voluntary bodily processes. But the line can shift again, and people sometimes learn that the entire bodymind is, in fact, their 'self.'
This often comes with a great sense of security, for the ego is constructed of memories, and when one lives there, one has a constant need to build up and defend the memory-self. But the 'centauric' self (to borrow Ken Wilber's term) is built upon felt awareness, which needs no building up or defending. The ego is entirely an abstract conception. The bodymind, or centaur, is a concrete reality.
Generally, conventional psychologists do not recognize any further redrawings of the self/not-self boundary. They stop at the skin boundary, for surely your skin separates you from the rest of the world, right? But this boundary is just as arbitrary as the ones that came before. This skin boundary, like
all boundaries that separate things from one another, is a product of the human mind.
When you imagine a flower, what do you see? The petals on top, and maybe the stalk too? Perhaps even the entire plant, roots and all. But what about the field in which it grows? You might say, "Well the field isn't part of the flower!"
But is that really true? A flower is no flower at all without a field in which to grow. In our heads, we can separate the two, in order to more clearly speak about them. But in actuality, there is no line that divides them.
There are many ways to illustrate this principle, this confusion of our ideas about reality with reality itself:
Where does my lap go when I stand up? What happens to my fist when I open my hand? When we see that 'lap' and 'fist' are just abstractions, there is no confusion.
Can you draw a circle that only has an outside, and no inside? Can you draw a figure without a background? We have two separate words - inside and outside - but the actual things arise together or not at all.
We say, "I saw the light flash," but there are not three separate things involved here - light, flashing, and I. The light is the flashing, and there is no flashing when there is no observer.
The point is, we can separate in our minds what is not separate in actuality. And the separation of one's organism from the total environment is no different. So then, the boundary line can and does shift in such a way that a person's sense of self expands beyond the individual bodymind, into the transpersonal domain.
And the final expansion, obviously, is to see, finally and concretely, that the entire universe is your body, and that there are no separate parts, but only an endless Whole.
And with that, we've come full circle to the essence of the mystical experience. But you had a second question: How does one experience this? Thankfully, it will not take you years of psychotherapy, followed by years of centauric feeling-awareness practice, followed by years of transpersonal practice, to get a taste of Infinity (all of that is precisely what is required, however, if you want to live consistently from that state of being; stages of growth take time and practice).
Sometimes, this experience just happens to people; You're looking at a beautiful sunrise and 'wham!' the sun is rising
in you. It also tends to happen when people are faced with extremely dire circumstances. The self has no choice at this point but to transcend or to break down.
But one can also bring this experience about intentionally, by creating a set of circumstances in which the boundaries can naturally dissolve. There are many people who teach you a lot more about how to experience this than I can. I recommend Eckhart Tolle, Alan Watts, and Ken Wilber. YouTube's a good place to start, and you should be able to find their books on Amazon, or if you have an Apple device, then on the iBooks store.
Here's a quote from my post in the "Changing Beliefs" thread. This quote is taken from Ken Wilber's writings, but the actual process has been around for a very long time. I think it originates with Vedanta, or perhaps Mahayana Buddhism.
Don't take my word for it that your awareness is infinite, that all things are arising within you. Take up a meditative practice (and stick with it, because it's not something that can be learned overnight) and see what you find. You can get a taste of infinity right now, though, even if only temporarily. Here's another passage from the works of Ken Wilber, which in turn is inspired by Vedanta:
"Notice first of all the broad, distinguishing marks of the transcendent self: it is a center and expanse of awareness that is creatively detached from one's personal mind, body, emotions, thoughts, and feelings. So if you would like to begin to work at intuiting this transcendent self within you that goes beyond you, the You that is not you, then proceed as follows.
Slowly begin to recite the following to yourself, trying to realize as vividly as possible the import of each statement:
I have a body, but I am not my body. I can see and feel my body, and what can be seen and felt is not the Seer. My body may be tired or excited, sick or healthy, heavy or light, but that has nothing to do with my inward I. I have a body, but I am not my body.
I have desires, but I am not my desires. I can know my desires, and what can be known is not the Knower. Desires come and go, floating through my awareness, but they do not affect my inward I. I have a desires but I am not desires.
I have emotions, but I am not my emotions. I can sense and feel my emotions, and what can be sensed and felt is not the Feeler. Emotions pass through me, but that does not affect my inward I. I have emotions, but I am not my emotions.
I have thoughts, but I am not my thoughts. I can know and intuit my thoughts, and what can be known is not the Knower. Thoughts come to me and leave me, but they do not affect my inward I. I have a thoughts, but I am not my thoughts.
This done - perhaps several times - one then affirms, as concretely as possible: I am what remains, a pure center of awareness, an unmoved witness of all these thoughts, emotions, feelings, and desires."
This can be summarized fairly easily. In your concrete and felt experience, all things - including your own thoughts and the entire manifest universe - are arising as objects in your awareness. Since you are something other than these things, since you are aware of them, you must therefore be something vast enough to contain all of time and space.
This part of you is the Witness, the Divine from the 1st person perspective, because it is infinite and ultimately beyond any description. And the final truth, present even now in your direct experience, is that the Seer is nothing other than all things seen. And this is what I understand God/Spirit/Mystery to be. It can be pointed out by saying what it is not, but even to say "It is everything" does not describe it, for that implies a "nothing" that it is not - and then it wouldn't be everything.
Here we have departed fully from "belief", and from metaphysics. After you have felt the Infinite, there is nothing that can be said one way or another to change the experience. It is unmistakable, and unforgettable.