Used to express criticism or disregard, aimed at the ultra-religious (see bible thumper) more specifically at extreme views from obscure Protestant sects. Usually said with compassion but can also be derogatory. See piss off
Them: We dont need to care for the world, Jesus will save us before anything bad happens
You: Science shows the way we have been living is unsustainable and we need to change that to survive. Even your own Holy Book tells you take care of the planet, so I'm just gunna assume you lost a few screws in your head. Please get some help. Oh and BTW the Pope says hello.