Religious and Rational? I say impossible.

Can anyone who believes in any of the major religions (Buddhism the possible exception), or any codified system of belief, be considered a rational person?  The amount of excuses used by the religious to defend their beliefs in the face of logical problems, historical atrocities, or factual evidence that contradicts their beliefs is seemingly unending.  If they ever have their back against a logical wall they fall back on the 'thats why you have to believe' line.  To me anyone who is religious can not be considered a rational person (dont worry spiritualists, I seperate you out from that list).  When your most cherished beliefs are based on nothing I dont see how you can be considered a rational person.