What is the source of the quote "Hell is reserved for those who believe in it"?

Question

I'm trying to identify the source of a quote, but I'm unsure of the exact wording. I think it's something to the effect of:

Hell is reserved for those who believe in it.

With an addendum (of whose wording I'm unfortunately even less certain):

The very worst level of Hell is reserved for those who believe in it solely because they are afraid that they will be sent there if they don't [believe in Hell].

I believed this was from Terry Pratchett, but I've had no luck tracking it down, and indeed I can't even find a reference to it anywhere online.

Answer 1

The gods of the Disc have never bothered much about judging the souls of the dead, and so people only go to hell if that's where they believe, in their deepest heart, that they deserve to go. Which they won't do if they don't know about it. This explains why it is so important to shoot missionaries on sight.

Terry Pratchett's Eric