But this Gemara is much less esoteric than the more famous one about him. Chagigah 14b has a very mysterious story about four who entered a Pardes. Pardes usually refers to an orange grove. I believe it has the same root as the modern day "paradise". Some even consider it an acronym for the four levels of interpretation for the bible. PaRDeS=PRDS. Peshat, Derash, Remez, Sod. The simple interpretation, the allegorical interpretation, the hinted interpretation, and the secret interpretation.
Whatever it is these four intrepid scholars were doing, it was something deadly. Without basic Qabalistic knowledge, the story does not make much sense. The story ends with Ben Azzai dying, Ben Zoma going insane, Acher tearing down the shoots, and Akiba entering in peace and leaving in peace.
After a bit of pontificating, the Gemara asks what Acher saw. He saw the angel Metatron sitting while writing down the merits of Israel. Now Acher was under the impression that none may sit while doing such an important task. Perhaps, he thought, there are two divinities.
As a punishment for not standing when Acher came, Metatron was punished with 60 lashes. And then, Metatron was given permission to strike out Acher's merits. When Acher saw that he was now doomed, he decided that he might as well enjoy the rest of his existence on this Earth. And the rest of the story is a combination of him descending into hedonism and defying his former masters/students.
And this story always troubled me. If Acher was wrong, then why did Metatron not correct him? He was not punished for sitting; he was punished because Acher was not supposed to see him sitting. So if Acher's understanding of how the angels in the upper echelons are supposed to behave was incorrect, then they should have corrected him. But instead, they punished both Metatron and him.
What gets me is that even the gemara itself does not bother to explain why Metatron was allowed to sit and why Acher's conclusion that he may have been some sort of demiurge was false.
And this, I am told, is why Qaballah is a forbidden subject for those under 40. Christianity split God into a Trinity, Qaballah splits him into 10 sefiroth. If one didn't know any better, one would think that the whole dichotomy of the Eyn Sof and the Sefiroth might very well be Gnosticism with a Yiddishe Zach.