The Great Work (also The Work, The Plan, The Divine Plan) is the spiritual work of improving our experience of creation (Sharp, 2015). There are many aspects to The Great Work. The Great Work is the evolutionary work of creating a Physical Unit capable of containing high levels of Consciousness, and the spiritual work of raising the vibration of Physical Creation to allow for the full descent of consciousness into physicality.
It is important to note that, contrary to what is typically taught, the Great Work is not an operation that we conduct on our "souls". The Great Work is not an "alchemical" work of soul purification nor is it an evolutionary march to individual advancement. That is a corruption. Our souls, our monadic sparks, are already perfect and require no moral, evolutionary, or spiritual development whatsoever. The physical universe (and your physical unit) are, however, another matter altogether. In order for dense physical matter to accommodate a "full measure" of Spirit, modifications have to be made and, in the case of the human Physical Unit, healing has to occur.
The Great Work can be considered a spiritual operation designed to modify physical matter. It is a collective process the outlines of which are summarized poetically in The Song of Creation.
Note, there are no "chosen" ones, no special places, and no spots where some are elevated above others. Everybody works together and, when the work is completed, everyone shares equally in the benefits.
Sharp, M. (2006a). The Song of Creation: The Story of Genesis. St. Albert: Lightning Path Press. https://www.michaelsharp.org/the-song-of-creation/
Sharp, Michael (2015). Lightning Path 200 - A New Story of Genesis: Lesson Two. Lightning Path Visit Course