I can't resist.
OUG,
you miss the point.
Poirot's point, I think, is that symbols (language--our symbolic order) precede all conception, including sense perception, and translates reality (real or imagined sensory experience) into the given symbolic order, i.e. that cultural system of symbolic meaning which always already precedes the individual's advent in the world. You are not master of your conceptions or your imaginings, or your epiphanies, or even your merely sense perception of this stupid, flat, objective reality (so the theory goes). All these "mediated" phenomena are made sense of via the symbolic order into which you are indoctrinated. Whoever cares to scoff at the the idea are welcome to offer a cogent rebuttal--but please no more arcane "knowledge"!
We are culturally constructed, mind, body and soul. This is merely logical.

Dear Poirot,

There is no need to reduce the notion of God to the symbolic because it already IS symbolic.

Having a notion of God can help to purify one's mind, one's heart, one's speech and one's actions, but it does not amount to knowing God.

You are very right to say that "without symbolism, you would be unable to mentally formulate any ideas, let alone one concerning your idea of God", but I am not after idea(s) ABOUT God, I am after union WITH God. No idea, as brilliant as it may be, can bring an end to our suffering.

"A "spiritual plane" is a way of describing a non-material realm of consciousness...it's not new knowledge at all, but simply a way to distinguish that realm from the material one."

The realm of consciousness is but a division within the physical/material plane. Science, at least psychology (being under dispute whether it is a true science or not), is dealing with it. I have nothing against scientific dissection of the universe, but that's irrelevant to our discussion of God and religion.

Yuyutsu,

"I am not after idea(s) ABOUT God, I am after union WITH God."

...but according to you, you ARE God. So what is there to unify, except perhaps an incongruity between your reason and your "spirituality"?

Dear Poirot,

It is one experience to have a recipe for a cake, knowing that a cake is possible, yet a completely different experience to actually eat it.

Yuyutsu,

As Squeers so eloquently pointed out above, the concept, the recipe and its ingestion are "all" made sense of via our immersion in the symbolic order

It's impossible to extricate yourself from this human experience while you are bound within its constraints.

Your experience of spiritually "eating the cake" is dependent on you first "intellectually" ascertaining that there is a cake to be eaten.

Yuyutsu

Are you a Christian? If so you are more likely to see images of Jesus in a piece of toast than say a Buddhist - such is religious embedding.

Then there is mass hysteria where many people claim to see the same event and make the same interpretation - this interpretation or claim of a miracle is likely to be influenced by their religious embedding. A Hindu is unlikely to see Jesus, but they may believe they have observed Ganesh.

So it goes...