Irrational for sure. Everyone's an athiest when they're born. The natural position is non-belief. Religion is a faith based belief system for something that cannot be proven. Hence, belief in religion is by definition irrational.

Now, if you are saying 'religion' to mean 'societal construct' or something like that, well, that is a different ballgame. Though I don't think you mean that, so the above applies.

Bottom line, the major religions of the world demand someone to suspend rationality to believe. Otherwise the followers would not be followers.

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