I would think this would depend on how it affects a person and whether or not the inconvenience is substantial enough to warrant some sort of action. If a Christmas or other celebratory display is one that is a visual annoyance, I'm not sure that qualifies as needing action. If the display offends a culture of people, that's another issue. If you are required to pay (through taxes, etc.) for such, you probably have a beef. But, all pay taxes for some things we might disagree with. I won't list them but, these....mostly....have some benefit to us that might not be readily visible
As for a Christmas or other religious display being allowed on public property, I can't see how that would be offensive to an atheist. No one is making anyone pay special reverence to it. What might be more inconvenient to the atheist, however, could be dealing with the stupid shopping frenzy that comes with the holiday season. The crowds, snarled traffic, price gouging in some instances, etc., are the real pain in the neck. ![]()
Here's a video at Google video that provides some answers. It points out things like:
An atheist boy cannot be a boy scout even though the boy scouts receive public funding and are allowed special consideration for the use of public lands.
That the constitutions of 7 states prohibit atheists from holding public office and/or testifying in court as a witness.
Because of blue laws that restrict what atheists can do because of others religious beliefs.
Because the words "under God" were not part of the Pledge of Allegiance when it was written but added after a campaign by the Knights Of Columbus, a catholic organization.
Because of the efforts to introduce creationism in our schools as part of the science curriculum.
Because national policy decisions on topics like stem cell research, abortion, the right to die are not being decided by rational discussion but instead by religious fervor.
It's a short 5 minute clip for those that wonder why atheists are making their objections to religion more prominent.

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