I've taken the position that JZ Knight is actually inducing an alternate personality when "Ramtha" is speaking through her. This condition would be assessed in the discipline of psychology, as Multiple Personality Disorder. I also believe that her followers do not quantify the supernatural existence of Ramtha, but rather are an example of our need to believe in the unexplainable.
A person diagnosed with multiple personality disorder has two or more distinct personalities. Although the disorder is mysterious and controversial, the concept that a person dissociates themselves from ordinary consciousness can be applied to JZ's case. As Ramtha, JZ can escape into the 35 000 year old, ex-warrior from Atlantis who commands crowds with his words of wisdom. The entity could reflect many elements of her life which she was unable to control or come to terms with. The majority of people diagnosed with MPD are women, many of whom suffered physical, sexual, or emotional abuse as children.
Little is known of JZ Knight's history before the introduction of Ramtha, however we could speculate that she may have experienced some trauma in her formative years causing the need to separate herself from reality. The mere fact that she chose a powerful male warrior as a personality may suggest she was dominated by a strong male acquaintance, and therefore would need to create an ultimate, unstoppable figure to combat her fear. JZ's suppressed fear may also be apparent in her notably reclusive lifestyle, allowing herself to be surrounded by a circle of followers rather than skeptics. JZ also claims that Ramtha doesn't wish to meet anyone on an individual basis, which would leave her alone with this person while waiting for Ramtha to come out. This might be too vulnerable a position for JZ to put herself in emotionally,