I was raised in the south and this was something instilled in me at a young age.when others sneeze I tend to say "mercy"or just "bless you". I think believers are untitled to there feelings and expressions. And I never know for sure what they might really mean, lots of people I know use these but are only trying to be pilite.for this reason I always simply reply thank you when I sneeze.

I do have a hope society will move away from religion, or at least question the idea that God is a given. I'm not an asshole, but that is a perfect time to let it be known that not everyone is down with this God concept. Your responses sound good to me. It's not an act of kindness to say "God bless you" to an atheist. Why do we have to pretend it is?

I say "I doubt it."

I often say "far to late for that" or "Too late, I am already in" with maniacal grin.
Yeah, I get odd looks.

I ignore the statement

I find being blessed for a sneeze extremely amusing and If someone sneezes near me I like to say. "I bless you, for you have sneezed." If I sneeze near someone I like to cut them off before they can bless me and say "Bless me! For I have sneezed!" Gets rid of the God involved. Or saying very solemnly. "Bless me, father, for I have sneezed." Using the same tone of voice people use when they say they have sinned.

Make their head explode. Ask "Which one?"

Copied from an earlier post:

A few years back I took a summer class and, thanks to allergies to weeds, I tended to sneeze a few times every day which was always followed by a small group chanting: "God bless you." My response was always along the lines of "No thanks. I'm not superstitious and I am not worried about the devil sucking my soul and leaving my body to suddenly die and rot from the plague like the good old days of Pope Gregory I.

And yes, I did often, not always, clearly respond with that response.

I explain to them that this custom was started by people who thought that when you sneeze your guard is down so the devil can take over your soul.

So do you know why people were taught to say that? Because "A sneeze allowed the opportunity for a demon to move in". So you immediately bless them.

Of course this is reflex in polite society - but the origin is more near the Salem Witch Trials.
Gees Growing up in Massachusetts sure was Educational!

Very Polite I say Thank You.

i say thanks. it is just kind of a reflex remark

I say gesundheit, just means 'health' as in good health in German.

Thanks! I was just about to burst into flames.

I'll take the well wishes and say thanks. It's not that they are preaching at me, or anything like that. Usually they are just making what they consider to be, a polite noise.

All one really needs to say is thank you!
It doesn't require an explanation or response back!

I just say thank you. It's just etiquette. They aren't trying to push God on me and I prefer not to explain atheism to someone who isn't interested unless they are being offensive

People do dumb things with the best intentions. I say thank you very much and think no more of it. It made them feel good doing it. I won't deprive them of that.

We're a gesundheit household.