It might be why you're an atheist, but do you think it would have swayed your christian self much? I highly doubt that your post would come near to deconverting anyone. Many religious people believe that souls are essential for creativity and intelligence, and they won't accept the "you're wired to see intelligence" argument if they disbelieve in evolution (not uncommon.)
To deconvert people to atheism quickly, I think you need a sledgehammer. I still haven't found a really good one. Here are some areas that might be promising:
Ask them why God won't drop a grapefruit from the sky to show he exists. "He loves me more than I can imagine, right? And more than anything he wants me to know him right? And he's all powerful, right?" To their response: "Why does God consider blindly believing in him in the absence of evidence virtuous? Isn't that sort of think a made-up religion would say about their god to keep people faithful?"
The Problem of Evil: why do innocent babies suffer and die from disease?
I've heard there are lots of contradictions in the bible. Maybe someone who is really dedicated could find some that are really compelling. Personally, I'm not interested enough in this topic to spend time reading religious texts, but more power to those who are.
A few moderately promising ones: Why does God heal cancer patients but not amputees? Why do different religious denominations disagree, when they could just ask God for the answer? Why would a benevolent God send people who happened to be unlucky enough not to hear about him to enternal damnation?
I think a very straightforward contradiction is here: http://skepticsannotatedbible.com/contra/horsemen.html
2 Samuel and 1 Chronicles are supposed to be parallels, telling the same story. Yet one of them probably lost or gained a zero along the way. Many christians that see this are foreced to retreat to a more 'soft' interpretation of the bible that allows for errors in transactiption etc. It's the closest to a quick 'n' dirty sledgehammer I have ever had. And a folow-up: Why hasn't this been discussed in your church? Surely, a group of truthseekers wouldn't shy away from such fundamental criticisms, even to diffuse them.
I've often had half-finished LW post ideas and crossed them off for a number of reasons, mostly they were too rough or undeveloped and I didn't feel expert enough. Other people might worry their post would be judged harshly, or feel overwhelmed, or worried about topicality, or they just want some community input before adding it.
So: this is a special sort of open thread. Please post your unfinished ideas and sketches for LW posts here as comments, if you would like constructive critique, assistance and checking from people with more expertise, etc. Just pile them in without worrying too much. Ideas can be as short as a single sentence or as long as a finished post. Both subject and presentation are on topic in replies. Bad ideas should be mined for whatever good can be found in them. Good ideas should be poked with challenges to make them stronger. No being nasty!