It might be good to get back to thinking of the Trinity in meta-cosmic terms.
The idea of God 'experiencing' or 'expressing' is cosmological, it's building an image from the ground up and so we tend, as I'm arguing with Wil, to build our own psychologies into the image of the Deity.
The same with the Trimurti of 'creation-maintenance-destruction', that's looking at the way of the world, and determining God thereby.
God, in the Christian Tradition, informed by Greek philosophy, transcends the classical 'transcendentals' of Parmenides and Plato, The One, The Good and The True. Aristotle focussed on 'The One' as primary, as both Good and True are relative terms and relate to rational creatures, who became conscious of the not-so-good and the not-quite-true.
Inevitably a discussion of the Trinity falls back into human language, but, being human, what other terms do we have? The point is always remember we are talking in analogous terms, and we tend to try and use precise terms because the topic is so easily confused.
On pantheism:
The Trinity is not dependent on, nor determined by, the Cosmos. God did not come into being with the Big Bang. God is not a created nature, as everything within the Cosmos is. God is not a 'thing' as other things are, and although we predicate certain aspects to the Divine – God is a Spirit, God is Love – like Truth and Beauty, these are the concepts of rational creatures.
We assume God to be rational. If not, then any debate is pointless!
But the world in not God, nor did God produce the world from His own substance or being. Creatio ex nihilo is fundamental to this issue. Matter is not a by-product of a process within the Divine.
As I have consistently argued, God is Immanently present to creation, indeed God underpins its existence, but that does not mean that God is creation.
Modern panentheism was born out of the Romance Movement, primarily German Idealism. To offer a perspective:
Abrahamic Theism
Sees God as being distinct from the world. The difference between the nature of God and the nature of Creation is infinitely vast. The Uncreate and the created. God is utterly transcendant, whilst simultaneously Immanently present to and in the world, but not as the world.
Pantheism
Stresses the identity of God and the world ontologically. Pantheism inescapably renders both the Deity and the world as conditional, all distinctions are temporary. There is often a strong sense of necessity in God's creation of the world, so that God as God must express deity in creation.
Panentheism
Maintains the ontological distinction between God and the world (I'm not sure you do, Wil?)
Panentheism generally emphasizes God's presence in the world without losing the distinct identity of either God or the world, specific forms of panenethism, drawing from a different sources, explain the nature of the relationship of God to the world in a variety of ways and come to different conclusions about the significance of the world for the identity of God.
Transcendence
God is un-contained, unlimited by any other being or reality.
Immanence
God's presence to the world.
Some panentheists see monotheism as limiting the affirmation of God's immanence. If the divine presence is indeed transcendent, then God's presence and activity within the world is an intervention of the supernatural within the natural. God, then, is absent from the natural except in specific cases of intervention.
This is not the case in orthodox Christianity, as we do not see 'immanence' in opposition to 'transcendence', rather we view everything as having God as its first cause, but also free, in the case of rational creatures, to make choices.
It seems to me, in dialogue with pan and panentheists, that:
1: It enables man to believe himself inherently divine. A kind of the 'I'm OK, You're OK' cliché of the pop psychology of the counter-culture.
(This was not the case prior to recent history. Man has never been so self-obsessed as he is today.)
2: It enables man to assert the freedom to choose is more important than the choices made. My choice is necessarily good, because I choose to make that choice. Its the point Mattieu Ricard (the French Tibetan Buddhist and media-regarded as 'the happiest man in the world') makes often – people exercise their freedom to make choices, blissfully unaware that the choices they make are nothing more than the whims of the moment. Look inside the mind, and there isn't a 'mind', there's a monkey, pushing the buttons and pulling the stops ...
I rather think the aim of meditation is the discipline of the mind. Beginner's Mind is ill-disciplined, and yet in this state the beginner wants to determine the nature and the course of the engagement.
Such is the mind that declares what the Trinity is, or isn't, with glib abandon.
Beginner's mind want the gratification, but is rather less disposed to put in the effort.
People who talk about 'finding what's right for me' are just affirming the whim of the moment, which becomes the habit of tomorrow. A self-fulfilling prophecy. At the start of the journey, you're not equipped to make any such determination. What is being sought is too often gratification.
As the wise old Zen master said. "Enough talk. Zazen!"
To even begin to understand the Trinity, you have to make space in your mind.
