I fail to even understand
Quite apparent.
how that relates to anything but the mysticism stuff that, frankly, I find to be the weakest points of BP, and the FS verse in general. (I really don't like the crap about the cosmic destroyers and stuff already and the triumvirate thing is so contrived just LOL-worthy).
There is no mysticism in BP; only mysteries not yet explained.
Nice to hear a major religion written off as lol-worthy, too.
A very...bad...easter egg if it fails to arouse any form of understanding or humour.
The fact that you don't understand doesn't mean others won't.
You're just going to have to trust that the story will be developed in an interesting way. Even as it stands, though, it's hard to take much of BP: AoA as genuinely mystical; there's nothing in there which defies physical law or requires godlike power. What you've got is some Sufficiently Advanced Aliens.
How they express themselves is, in all probability, determined by the beliefs and memetic array of the individual they are speaking to. 'Vishnu' and 'Brahma' are natural complements to Sam's existing concept of 'Shivans'.
Anyway, to wrap it up: Droid803 is wrong. Those of you who are looking for a deeper meaning are right.