Buckle up for an info dump, Shmoopers. Hiro's rundown goes like this: He's on the Raft looking for Enki's five-thousand-year-old software that can change people's brains.
Naturally, his homeboys ask for some clarification.
Basically, everyone has two kinds of language in their brains. The language they're speaking now is acquired, and it patterns their brains as they learn it, while the underlying language, however, is based on a deep structure present in everyone's brains.
Speaking in tongues or babbling is the output of the brain's deep structure. But there's also an input side, which means that someone who knows how to speak the deep structure can say things or show you things and thus bypass your conscious control of your brain.
This early language was like the mother tongue of humanity back when primitive societies were controlled with rules called me. All this was possible due to a metavirus, which infected all of humanity and caused other viruses (along with knowledge) to propagate.
According to this model, civilization itself started out as an infection. Like whoa.
Information like how to bake bread became self-sustaining, and people who had access to that information obviously survived better than people who didn't. So the information (or the me) spread like a virus, civilizing people in its wake.
Enki, our ancient hacker friend, realized that civilization's good and all, but the viral part of the civilization just kept transmitting the same old viruses. Nothing changed. Culture didn't evolve. So he decided to fix it.
He created a nam-shub that would reprogram that brain of anyone exposed to it, cutting them off from the Sumerian language. That was Babel, and it forced humans to develop other languages and to create new me. People had to become creative and use higher portions of their brains to survive.
However, the cult of Asherah continued here and there. They could biologically transmit the virus through bodily fluids (thanks to sexy temple prostitutes, who also nursed orphans). The Asherah virus, which is both informational and biological, resides in and actually changes the brain.
Hiro ties this in with the birth of religions of the book (such as Judaism, Christianity, and Islam), which had strict rules about how to copy their holy texts—this was one way of minimizing Asherah spread, by keeping their information clean and pure.
Christ's gospel represented a new nam-shub, but those in power hijacked it and turned it from a religion without hierarchy into one with tons of hierarchy. And so it went throughout history.
Glossolalia was not cool within mainstream Christianity, but it would pop up on the fringes occasionally, and the Church even accepted it on occasion when it was helpful in converting "savages" who spoke different languages.
Then Pentecostals started going mainstream and gaining acceptance. The result is that the cult of Asherah lives on in the Reverend Wayne's Pearly Gates.