Imagine your soul as a drop of water, independent for a time, but able to seamlessly integrate back into the ocean. To return to the Pleroma would be to return to the conscious waters of God itself, of you.

There are varying interpretations on ascending (and really it should be thought of always as an inward descent) and how many heavens/densities/realms/dimensions there really are. Think of it all like a heavenly conscious fractal stemming from a source mind that is God; splitting itself infinitely into new conscious forms with amnesia so that it may experience itself.

The OP is posting about a recent theory that the 'light' people speak of in NDE's that appears as a loved one, an enlightened master or sometimes just light, is actually a trick of lower density beings not connected to the higher realms, the Pleroma. The light is said to express love and acceptance and a desire for you to be with it and follow it, but it cannot force you to do anything. Manipulative love. These beings need your soul here to generate karma/energy to sustain their existence and also they fear humans for we are created in the image of the alien God, the Aeon Pistis Sophia who spoke to Yaldabaoth in the waters of Chaos. To the blunt, the Archons fear humans more than anything and will stop at nothing to completely subjugate and rule them. I've dived off into Gnostic mythology here but if you are at all interested I encourage you to read further.

A lot of which I am speaking on here is sourced from the Nag Hammadi library texts as well as general teachings of Platonism, Hermeticism, and Gnosticism and the modern, Don't Go Into the Light/Reincarnation Soul Trap/Matrix theory that has been developing, which is of course largely inspired by the ancient mystery teachings with a healthy dose of our current zeitgeist.