If I said that I'm an atheist in your nation?

[Kaifunasia]

What would happen to me or anyone else if I were to mention that I were an atheist in your nation?

In Yakus, I/you would probably face an awkward stare as people try to figure out why it was important to mention such a thing, but most people do not care about religion. Some strongly conservative/deeply religious/countryside dwelling folk might try to convert you or condemn you to hell, but overall nothing much would happen. Catholicism is the largest religion in Yakus, followed by Protestantism, atheism, Buddhism, Daiwatai and Islam.

[The Intergalactic Universe Corporation]

No one would actually care

[Qandaristania]

You'd get executed.

[Punikstan]

No one would actually care

This, pretty much. The freethinkers will praise you, though.

It'd be weird if you weren't.

This too.

[Switzo-Polish Republic]

What would happen to me or anyone else if I were to mention that I were an atheist in your nation?

In Yakus, I/you would probably face an awkward stare as people try to figure out why it was important to mention such a thing, but most people do not care about religion. Some strongly conservative/deeply religious/countryside dwelling folk might try to convert you or condemn you to hell, but overall nothing much would happen. Catholicism is the largest religion in Yakus, followed by Protestantism, atheism, Buddhism, Daiwatai and Islam.

Everyone is an atheist in my nation. I do not use the stat for religion.

[Federated Kingdom]

dragged out into the streets and publicly stoned to death by members of our inquisition™

on a serious note nobody would give a shit apart from maybe some fundamentalists. we're a liberal democracy.

[Tinhampton]

"Do I even care?" - the man on the Tinhampton omnibus

[Uinted Communist of Africa]

Okay first of all....I see Switzo-Polish Republic copied and paste the revolution signature( I know because I'm the only one with hammers and sickles)

Secound of all if you claimed that in my country you would just be stared at....and then a mob of preachers would make you disappear.

[Markomann]

Same as tons of people?

[North Isseggggnignigsegigisegggg Islands]

People would personally disagree with your lack of faith, but they wouldn't do anything else. If you start claiming that religion is "outdated" or "stupid" or whatever, expect to get into a heated debate.

[Turkish-Turan]

It depends on the city. In the biggest cities of Turkey; Ankara, İstanbul and İzmir, probably no one would care (Unless you say it in a wrong neighborhood.). In the smaller cities people may look at you like they're disgusted and if they are more religious than others, they may try to convert you back( Also wrong neighborhoods are in these cities too.). However, if you said that in a very religious city, nearly extremist, like Konya, get ready for an heated argument then a public beating.
( Wow this game is so realistic for some reason wow )

[ATLANTIARIV]

My People will surely answer : " Great for you, but we don't care!

[Striagro Uspil]

People would personally disagree with your lack of faith, but they wouldn't do anything else. If you start talking about how religion is "outdated" or "stupid" or whatever, expect to get into a heated debate.

Same with my people but the heated debate would end up with my people saying to you "YOU NEED JESUS" storming off while simultaneously earning the title "That One Atheist In Town"

[Ban Pho]

You'd upset a bunch of high-ranking buddhists

[Fahshist Yuflijan]

It's illegal to be anything but Atheist.

So, you'd be monitored for any unorthodox thoughts (religion and other political ideologies.).

[Soyuzistan]

As IUC said

No one would actually care

[Oceara]

People would shrug it off, finding it not important to their daily lives what others' personal beliefs are.

[Rejistania]

People would rephrase the question to ask what your rites are. Like atheist Europeans celebrate Christmas, atheist Vietnamese celebrate Tet, atheist Rejistanis often still celebrate their holidays.

[Sacred Margarine]

No one would actually care

[Galeion]

Nobody would really care but the rebels in Franklavakia, who'd probably hunt you down and kill you and your family.*

*that only applies if you said it to one of them

[Benign Retrofuturists]

It'd be weird if you weren't.

[Jefferson Free State]

Nothing would happen, though the Free State is a secular nation, no one really cares too much if you're religious or not, so long as you behave how a Jeffersonian is expected to.

[Vescus (Ancient)]

We would like you more.

[New Amapa]

Pretty much everyone would be fine with it and wouldn't care, but they would actually look down on you if you were religious.

[Carmini]

If you were to profess to being an atheist in Carmini, not a lot would happen. Carmini is a notably faithless country, with less than 50% of people adhering to a religion and the majority either being agnostic or atheist. Even the Queen, Juliana, is officially an agnostic, though there are rumours that she is in fact an atheist and only identifies as agnostic to prevent her from possibly alienating religious citizens.

While atheism is 'the norm', there are outliers who are strictly religious, of course, but a long-standing tradition of freedom of religion precludes most Carminians from discriminating based on personal beliefs.