I think the ultimate crazy conclusion from positivism is the Eliminative Materialism.
Eliminative Materialism says the human consciousness does not exist because it cannot be scientifically verified.
So to eliminativists God is not the only delusion but the human consciousness is a delusion too.
That's the logical conclusion if materialism is the only system you accept.
Before someone says my definition of Eliminative Materialism is wrong, here's a link: