A number of buddhist sects/schools hold no belief in any god... It is a religion, they are not irrational. It is a major religion.

> And as for educated. Perhaps there isn't a conclusive study on the subject, but it is safe to say that the more educated you are, the less likely you are to be religious, particularly fundamental. http://en.wikipedia.org/wiki/Religiosity_and_intelligence

Correlation or causation? I don't really have time to read through all the studies, but St Thomas Aquinas is a good counter example of that premise, very analytical, very religious...