Not to mention the detrimental effect such knowledge would have on mankind. Their would be no faith and without faith, how can you have salvation?
God: You are a sinner, repent.
Sinners: Sure, yeah, um. Okay, I repent…
God: Of course you repent, you have nothing to lose. You already know what’s a sin and what isn’t, maybe your confessions are a little disingenious.
Sinners: Yeah, that’s true…I think I see your point.
God: Good, now go to hell…
Just one thing to add to this, Genesis also doesn’t say that the serpent was Satan, it merely calls it “the serpent,” with no further explication. It’s just a good old fashioned talking animal myth.