*how* is one to be Harvested?!

[Siren]

So then Siren, the spirit is the column of light in between us and the Creator ? And then animals do not yet have this column?

Yes, a column, or tube or vortex, if these image serve you to visualize the concept. But instead of going up, it goes in.

All entities are a mind/body/spirit complex. Generally-speaking, 2D entities have not yet activated, shall we say, their spiritual potential/faculties, which are characteristic of the more conscious yearning or desire to find/discover/know the Creator in and about themselves.

It is basically because the entity is able to ponder that "there's something else out there" and subsequently contemplate upon its own existentialism (its own origin, meaning and purpose of being alive), that the spirit complex may be said to come into activation.