The Holy Spirit (See The Holy Goh for christian concept) is the layman's term for an now-extinct bio-luminescent bacterial infection. The name is a reference to the common assumption at the time that all diseases were either demons or spirits. It was assumed that any disease that would cause a person to glow like the Heavens must be Holy; thus the name. As the bacteria went extinct after such a short time on Earth, there is no physical record for scientists to study, and thus they are left with only anecdotal evidence that it ever existed in the first place.