You honestly would not believe how often this one comes up, or how many answers it inspires. :-)
Personally, I think Ray would then have to destroy the world alongside Gozer. Other than that, I really can't answer that, because it's too terrible an alternative to even contemplate.
There's no way to
prove godhood, really…it's one of those "
is you is, or is you ain't?" things, if you'll forgive the vernacular.
Makes you think, though, doesn't it? There really is a lot more depth to the
Ghostbusters films than the general public might recognize.