Mystery
It is the very nature of the essence of our Being that it is
a mystery. It is a mysterious essence. Its mystery is not due
to a limitation in our capacity to understand it; its mystery
is intrinsic to its reality. This mystery, this sense of indeterminacy,
has been explored by many people, and many teachings and formulations
exist to describe it. ...the mystery of Being can be seen as having
two different implications. I believe that the more fruitful one
is not that there is nothing you can say about it, but that you
can never exhaust what you can say about it. We can describe it
and talk about it forever. So instead of calling it indeterminacy,
I think a better word is inexhaustibility: the mystery is characterized
by the fact that it is inexhaustible. You can never know it totally.
(Spacecruiser Inquiry, pg12)

Mystery of Being
We need to remember that the essence of Being cannot be finally
determined – this is what I call the inexhaustible mystery
of Being. You can know it and know it and know it and know it,
but you can never exhaust it. This is true about any manifestation
of Being – in fact, about anything in life, anything you
experience. You can know the experience precisely but this precise
knowledge is never final. It is this ultimate mystery that allows
the unknowingness to continue being there, for regardless of how
much we know, we still don’t know. There is always unknowingness.
(Spacecruiser Inquiry, pg 118)

Inquiry and mystery
Being reveals its mystery through revealing its truth. By revealing
to us more of what it is and how it functions, being shows us
how little we know. It also shows us that the more we know, the
more we know how little we know. The journey of inquiry takes
us from knowledge to mystery. Our inner guidance reveals to us
the truth and richness of our Being, but the more it reveals the
truth and richness of our Being, the more we are in touch with
the mystery. It is a strange paradoxical situation: inquiry reveals
to us more and more about our true nature and about reality. However,
the more knowledge and understanding we gain through this revelation,
the more we approach the depth of our Being, and its essence,
which is mystery. To go from knowledge to mystery means to jump
into the unknown. (Spacecruiser Inquiry, pg 75)

Reality and mystery
The real world is nothing but the beauty that expresses the truth,
the reality, the mystery that, in itself, is completely unknowable
and inexpressible. Seeing this, we see that God is not somewhere
else, that spirit is not something else, it is nothing specific,
nothing in particular, nothing in the past or the present or the
future, here or there, and has nothing to do with these. All these
things are words anyway. God is a word. Truth is a word. If we
are simply knowing a word, what is the mystery then? The mystery
is not somewhere else; the mystery is nothing but our world, reality
itself when we truly perceive it. There is nothing else, nowhere
else; there is no heaven somewhere where God lives, running the
show. This is God and he’s not running the show, he’s
just living. (Diamond Heart Book 4 pg 264)

Mystery of Absolute
We can know it, but to know it is to know it as mystery, the
ultimate mystery from which all being and knowledge arise. To
feel the explicit intimacy of its nonbeingness and the see the
absolute aliveness of its emptiness is to behold a majestic mystery,
luminous and deep, awesome and enveloping, yet inviting in its
annihilating touch and caressing in its melting embrace. We behold
a mystery that we passionately wish to know, and we know that
to know is to cease being, yet we long to the embraced by its
annihilation and love, to be taken in by its cessation. To know
it is to cease, and to cease is to know it. To know it is to not
know it, but to not know it is to know it. To know it is to know
it as mystery. It is the mystery that must remain a mystery, which
cannot but be a mystery. Its being a mystery saves as from the
obsessions of our mind, and from the false securities that our
false self thrives on. We behold it as mystery, a mystery that
by remaining a mystery liberates us from the traps of the manifest
world. We learn to live in mystery, to be supported by ultimate
insecurity, and to love the flavor of nonbeing. (Inner Journey
Home, pg 401)

We can know much about it, but the more we know the more we realize
how much we do not know, and how mysterious it is. In other words,
our knowledge of it, regardless how deep and exhaustive, never
exhausts its truth, never encapsulates it. It is knowable, for
if it is unknowable then this is its determination, but it cannot
be fully knowable, otherwise it will be determinable. It is the
inexhaustible mystery. (Inner Journey Home, pg 403)