The natural progression of intelligence is from believing to unbelieving to know the cycle.
A believer, atheist, is a bit dumber than an atheist. You just need an open mind to see that all around you. Atheists can be more rational and accommodating than an atheist.
This is because an atheist is more courageous. He has started to question inherited beliefs and teachings he was given since birth. In short, he is using his mind at a higher level than a believer.
A believer never questions, and it is out of fear of what he may find out. It takes guts to question all you have known for years.
If an atheist goes beyond simply reacting and rebelling against believing, he is at the threshold of knowing. Knowing is coming to a point where one can see the WHOLE picture.
It is a higher dimension of intelligence, higher than believing and unbelieving. Think of a triangle. At the bases of two extremes, think of them as belief and unbelief at either end.
The apex, which is beyond and above both is representative of knowing. From the apex, one can see the stupidity and futility of the theist and the atheist.