Just because the Christian God exists is not a reason to become Christian.
Being a Christian implies you worship the God. I think that any God that would destroy the ancient and fascinating system of life on this planet on a whim isn't worth anything.
Not to mention he's a sadistic prick.
It's not exactly a whim. Armageddon's purpose (as I understand it, at least) is to destroy the remains of the world at the point where it's been overrun with sin.
If you make a group of robots, and most of them start going haywire and start to destroy everything in site, wouldn't you, as the creator, put the working robots in a safe place and then dismantle/deactivate the rest?