Why is it that most atheists in western society were former Christians?

Because the truth hurts!

Because Westward is where Christianity spread out of the Middle East when Paul headed back to Rome. At that point, the West was pretty much Pagans and a few Jews.
Pagans were chased out of town ( or skinned alive and burned, like Hypatia) by Christians, Jews were marginalized. That only leaves Christians to change their mind. Numerically speaking, who else in the West would become an atheist?

It’s just the larger numbers. I know plenty of Jewish atheists.

I never considered myself christian ever, but, I was raised with a very diverse religious background and being an independent thinker and a knowledge seeker I could no longer deny that the odds of some magical “God” were just that, figments of magical thinking conjured up by ancient ones that could not explain the mysteries of the universe and hence, needed to create a deity to appease their fear of the unexplainable and the unknown.

I didn’t like singing and genuflecting. I hate insence. So it was natural for me to turn to atheist non beliefs. Also I don’t want God to own my soul I would rather keep it for myself.

why is it that most adults on earth were former children?

I think you’re making a huge assumption about the origins of atheism in Western society. Where is your count of those people who were former Christians vs. former anything-else or always-atheist?

You may of course be correct for the reason that @janbb and @ragingloli refer to: Most people in the US, to name a country that I’m intimately familiar with, are or have been or were raised as Christians. But I don’t know the incidence of atheism among Jews, Hindus, Muslims, Buddhists and other religions here. Those folks could all turn 100% atheist, for all I know, and their numbers still be dwarfed by the relatively much smaller percentage of former Christians who have become atheists.

It’s a pretty silly question, really. You might as well ask why most atheists are human.

@CWOTUS Well to be fair I never made any assertions to imply that atheism originated out of Christianity. In fact I would even wage that atheism most likely predates the oldest form of spirituality.

If you take a look at the link I provided in my original post. There is a chart that goes through a full spectrum of what atheists were prior to them being an atheist and the amount of those you have always been non-religious. The server on the website I provided you might be low, so you may have to wait a bit until you can access it.

I don’t think its a silly question. If you think I might as well be asking why most atheists are human, I’m afraid you’ve entirely missed the point. The point is to question the religions of Christianity. I’m questioning why there was such a decline. This has less to do with identity and more to do with persuasions.

Edit: It seems that the server is not responding on my source that well. I managed to get it working a while ago. So I have uploaded the chart from the website to Flickr. So you can view it here if you wish.

Because there is a huge amount of Christians in the Western Hemisphere in the last few hundreds years.

They estimate 40% of Jews are Atheists, or identify as secular. That’s probably much bigger percentage than former Christians, just we Jews are a tiny number in the world.

I still am a Jew, I’m an atheist, and I was raised by atheist Jews. That’s not uncommon.

Most of Western society is Christian of some sort.

You can thank Constantine for that.

Are there no atheists that ever become Christian? People grow up and decide for themselves if they will or will not follow a faith. We do not all decide to follow what we were taught. In the western world, more than most, there are no serious consequences for changing your faith or deciding you no longer believe. You simply can’t say that for the whole world. In some parts of the world being an atheist would have some real social to deadly consequences. Or even changing your faith.
Not that it isn’t changing in the west. Muslims are being persecuted more than atheists.

@Pandora Yes there are. In fact, I was an atheist who became a deist. We are all free to follow our own path.

Yes, it is very true that especially in the middle east being an atheist or even a Christian can be quite a taboo thing to be admitting. Think back what happened to Raif Badawi (who wasn’t even an atheist, but just said something controversial about Islam).

For anyone that is interested, the full survey is available here. It includes more than just religious background.

Added myself, not that the US needed to be more green.

@Seek Ah sure why not? You might as well be counted in

Because most in the west were raised with a Christian upbringing. It’s simply a numbers game. That and the fact that most western nations allow for free expression of religious belief/non-belief (at least legally, that’s not to say you won’t be shunned by friends/family/your community). I suspect that you would find many atheists who were Muslims as well, if the majority of the world’s Muslims lived in nations where they were free to express it.

For what it’s worth, in my own anecdotal experience, I come across a greater percentage of atheist Jews than I do Christians (though, of course, Jews are a much smaller population than Christians). Perhaps because Judaism doesn’t put an emphasis on eternal punishment like Christianity does.

@Darth_Algar I think it has more to do with Jews being raised to question. Also, an emphasis on scientific reasoning. Plus, don’t forget the biggy, we have been enslaved, tortured, and killed so many times throughout history it’s hard for a lot of us to believe there is a God who allows such things to happen.

Christians dominate in the West, that’s for sure, so the majority of almost any large group is going to be dominated by Christians.

But I also think it has something to do with Christianity maturing. Splintering into dozens of non-violent factions. Allowing people to live peaceful lives within a Christian family and/or community and outside Christianity.
There may be as many Muslims that have doubts, but they’re largely not allowed to express that in any way.

For another thing, it’s not a self-imposed death sentence in the West to say, “Yeah, I don’t believe.” At least, not any more.

Depending on the security that poll takers can promise to respondents, there may be a whole lot more Muslim apostates than those who identify as such. I’m sure there are a ton of Muslims (just as in earlier years there were an equal number of Christians – “nominal Christians” anyway) who profess belief but don’t feel it a bit. But it’s not safe for them to say so in the places where they live, or to the people they live with.

Because Christians begin indoctrinating their young at an early age.