What is the soul and how may I approach it?

[Sacred Fool]

I somehow got the sense that this 'stair of light' is a metaphor?

Whether it's stairs, a ramp or a golden escalator, what they're talking about is a gradation of intensity of light/love.  The grade of light/love at which one feels comfortable (3D or 4D) indicates what level planet (3D or 4D) a newly dis-incarnate self will take birth upon to do their work in consciousness.

The '4th density' here correlate with the '4th chakra', the heart chakra, and those who choose negative path (STS) somehow 'skipped' the 4th chakra. Maybe it's due to their resistance to 'release' or 'detached' from their 'identity' / the limited self? And or maybe also due to lack of willingness to also attached to another 'identities'? The "Others"... including the soul's own higher self.

I'm on the understanding that all identities are part of it's own respective higher self including those who are still on STS illusion, thinking that they're separated from others.

As I read the material, what you say here is a bit askew.  The 4D negative entity progresses into 4D because it has learned to love deeply; however, this love is not registered in the heart chakra, so it's a bit confusing.  4D+ love is of the heart and radiating, wanting the best for all in an equal manner.  4D- love is magnetically inwardly drawing of energy, therefore it's concealed and difficult to read.  It feels all are best served if it, above all, is given respect and power.  It feels that its ascendancy in power is the best way uplift you and me.  Think of your basic selfish guru.  So, it's not entirely detached from other entities, it's just very particular about the kind of attachment it will allow.

There is only one higher self, not a separate one for positive and negative 4D & 5D entities.  This is because the higher self experiences reality beyond the point of needing to have a polarity, therefore, it has no discomfort with either one.

The point of the post was to speak about how to approach, or how to experience, the soul, and the suggestion is that this is done by exploring and freeing up the experience of the various levels of inherent consciousness.

I understand this as exploring the fragmented soul(s).

I'm so glad, jafar, that you mentioned that your conceptual framework for this stuff is built around what you learned about D.I.D.  Up until that point I really couldn't follow you, but this now makes a lot of sense to me.  You see, when I was of high school age, learning about what was then called Multiple Personality Disorder (MPD) was very significant indicator to me that consciousness is far, far more interesting--and powerful--than we are casually led to believe.

So, given something of a shared background, I would say the following about how I understand these two models converge or overlap (MPD and the Ra/Q'uo readings). 

The critical elements I would point to distinguishing the idea of the soul which has many incarnative experiences from the person who has many personalities are these.  (1) The soul purposely incarnates in different contextual environments in order to gain further experience as it grows in spiritual maturity, whereas MPD is brought on by severe trauma and is unintentional.  (2) The incarnations of the soul--such as you yourself right now--are in the process of developing spiritual awareness wholly independent, usually, of the other incarnated selves; however, the multiples, being fractured bits of one composite personality, DO NOT (as I understand it) grow spiritually on their own at all.  Rather, the composite individual may grow as the multiples are glued back together, so to speak.

And so, the business of stitching together the multiples in a patient is important for that patient's mental health on the Earth-plane level, but the assembling of the soul's incarnations happens at the level of the higher self in late 6D and is not our worry here in 3D.  However, having contact with the soul, with spirit guides, etc. can be very useful, depending upon what kind of service one wishes to offer.  And, in contrast with the MPD/DID situation, this is all about exploring finer capacities of consciousness, and not so much about organizing one's basic experience of 3D life.

I hope that provides some avenues of thought for you.
   

To go back to the OP peregrine,  isn’t meditation the easiest way to access the soul ?

Yes, surely.  The next question might be, how can one explore such things in meditation?  And that's what the OP was sort of about.  Of course, this also prompts the question (which I completely failed to address in the OP, just stumbled over above in my response to jafar), why would anyone want to contact their soul?  And I would agree with what I already noted above: doing so may help facilitate service they wish to offer, service to the planet, for example.

I have read or listened to accounts from other parents in similar moments, so my case is far from unique.

Yes, we sometimes access our "guidance system," as Q'uo likes to call it, in times of duress.  Q'uo recommends doing so all the time, and that might just be a good idea.