“Gurdjieff maintains that people are not by nature, immortal, but we do have supernatural potentials embedded in us to attain immortality. However, we have to consciously actualize them, otherwise when we die, that will be it”.

Given our recent conversations, I assume you believe that human consciousness is one manifestation of an eternal ground of being (Brahman). How then is it not immortal?

Are you saying that Gurdjieff doesn't believe in an afterlife? Or merely that at death a human's consciousness remains at the same level, and cannot make any further progress?