They should have gone with the idea that the 'god-face' villain was Gary Mitchell.The original concept had God and Satan in a final battle in front of Kirk, Spock and Bones. That is nothing like any Star Trek that I've ever seen.
That at least would have brought the movies and show full circle.
It also would have added another reason why Sybok chose to infiltrate the Enterprise, he was unknowingly being influenced by god-Mitchell to bring Kirk to him.
As for how Gary ended up in that place...,
At the last second just before the boulder landed on him, he threw his consciousness out into the universe.
It then drifted as a disembodied entity for decades before eventually ending up drawn to and stuck within that energy barrier.

Last edited: