While I admit to seeing religious belief as irrational, I have clear memories of my own irrationality in that regard.
First: Try and understand my position.
I'm very frustrated. Imagine that you are in a room full of ex-atheists who had been converted to Christianity. In no time they begin a discussion about their new-found beliefs, remarking with incredulity how they had ever believed all the irrational premises and contradictions of atheism:
'I don't know how i could have ever thought that'
'I know it seemed very logical at the time, but now i realize how much my emotions tampered with my
better judgement'
'It clearly wasn't based on reason. It was so highly unscientific and so full of contradiction'
Sitting in that room listening to those men what would be your first thoughts?
You could just decide flat out that they were wrong, that they were the ones making faulty assumptions based on claims with no evidence.
However, this would be very small-minded of you. (To put in a different way, it would be mighty Christian of you.)
But these men aren't stupid, not by a long shot.
If you are like me however, you would use this opportunity to reevaluate your beliefs based on what you are now hearing. The fact is these rational and informed men find atheism ridiculous.
Unlike them you are still an atheist. Your logic makes perfect sense to you but is nonsensical to the men whom i might add are looking retrospectively at your position. Why?
If you take time to follow this thought through you will come to the eventual conclusion that there has to be something that is effectively preventing you from sharing their views. A dividing line perhaps between your views and theirs and you will want to know what that is.
Intelligence is not an indicator of logical thought and critical thinking, alas. The human race would be so much better off if that were true. I know several Christians I regard as smarter and more widely experienced than myself, including my Harvard-educated father. It's just that they refuse to apply their intelligence to their religious beliefs objectively.
Why believers fail to do this varies, and I agree that generalizing on that topic is unfair and often unproductive. Early indoctrination, fear of death, wanting social acceptance, simple credulousness and other motivations come into play.
As I said before, I don't hold that my atheism by itself makes me "better" than a believer. I have a number of irrational behaviors; I procrastinate about almost everything, for instance. It's where someone's god-belief has a harmful effect, on their life or others, that I see atheism as often offering an advantage.
I am a Christian.
I believe wholeheartedly the tenets of my Christianity, not because i was taught believe them but because they make sense to me as an individual. This is not to suggest that other views and religions do not make sense, but that when held up to the scrutiny of my rational mind, i find that tenets of the Christian view are more convincing.
I do not think that i am stupid or in any way mentally impaired. When listening to arguments of the atheistic standpoint i do not feel particularly uninformed. Being a Christian does not make me more intelligent that anybody on this site. I cannot however take the fact that you hold different views as inference that you must know better. If atheism is the inevitable destination of all logical and reasonable thought, then i think and reason as much as anyone. WHY DO I STILL BELIEVE IN GOD?
Am i missing something? Some sliver of knowledge, some defect in my reasoning, an unresolved personal bias or prejudice?
What? What am i missing?
One's religious beliefs are largely dependent on culture and early socialization. Please correct me if I'm wrong, but you're most likely from a Christian family and did most of your growing-up in a predominately Christian culture (the Americas, much of Europe). Do you really think that played no part in your personal beliefs and biases?
I don't think you're an idiot or mentally lacking in some way. All you're missing, as best I can tell, is experience and education. That you're admitting doubts about your faith, even in the anonymity of the internet, speaks well for your honesty. Again, I encourage you to read about atheism and religion (from academic, non-sectarian sources; objectivity on this topic is important) and continue to engage with atheists, here and elsewhere.
If you're wondering "when" you will suddenly deconvert, be aware there's no universal schedule or method (if
only!! 
). My own coming to atheism was a gradual process; I can say roughly when it happened, but there was no definite "Aha! Good grief, what an irrational person I was yesterday," moment.
