I must take exception with the idea that Orthodoxy cannot coincide with more rational approaches. I am a product of the Western world; I think in rational terms and have always had difficulty with what seems to be a constant attack on West for that reason. I have found Orthodoxy, as far as religion goes, to be the most rational out of any branch of Christianity I've known. Our theology, while mystical, still seems rational to me. Clearly there are aspects of our faith that we dare not attempt to explain, but even that is rational -- attempting to explain the unexplainable, like the Roman Catholic Church has done in many cases, is in fact the irrational position to take, not ours. And when it comes to the existence or non-existence of God, clearly there is no absolutely rational and logical answer to the question; however, the fact (and I do posit that this is fact) that life has no meaning apart from meaning imputed to it by someone is cause to search for a someone other than ourselves. That search leads to God, and by association, His Church. So though I can't prove that God is there logically, I still think it is reasonable and rational to search for God and have faith by extension. The atheist essentially concludes that faith is unnecessary, but in my own experience, the only way to derive any meaning to my existence as an atheist is to de facto make myself into god. And it's been a failed experiment every single time. Again, I have found it reasonable that the source for the meaning of my existence lies without, and it is reasonable to search beyond what is tangible for something so profound.
My two cents as an Orthodox gone atheist and returned.