>Which actually works here. After I've responded to that kind of greeting (and "bless you" and such) with "sorry, doesn't apply, not a member", the people really stopped doing that and I respect that. The implication behind those is that regardless of our (un)belief, we are, in their eyes, the creatures of their imaginary friend, willy nilly and without any choice in the matter. Well, I didn't think so and asked for that kind of opinion to remain undelivered. And we lived happily ever after.

I accept them as fellow humans, for that.

>Are they offended if you tell them to deliver the greetings to the sender? As in "Send him my regards, then". BTW, I've heard this in other parts of Germany as well (I think both around Düsseldorf and Stuttgart), but then those may have been cousins of my hosts.

I guess they are a bit offended. At least they have a chance to take the joke. If I answer plain "Guten Tag", that's freezing.
Normaly it's bavarian, southerners. We are unable to lock them there. Freedom has black spots, you know ...