I think we are all be far too restrictive in our definition of "reason," and displaying not a small amount of arrogance in so doing.
Consider these statements:
"I am hungry, therefore I will eat."
"It is raining, therefore I will find shelter."
These are expressions of reason, and they are displayed in almost every human being, other than those who have the most profound limitations.
Reason needs nothing more than observing circumstances in one's environment, and then determining a course of action as a response to those circumstances.
Now we might all believe that, "Even though I am hungry, I will not steal this person's loaf of bread," is a more rational thought than the first statement above--but not so. For it relies on a new piece of environmental information--the property interest of another person. And then, "Neither I nor my family have eaten for three days, so I will steal this loaf of bread anyway," brings in yet another circumstance.
To suggest that no reasonable person could subscribe to religion is to substitute one's own perceptions and beliefs for another's. And though many of us here are mind-blind, that is no excuse for chauvinism.
Every human being is capable of rational thought. And although some incorporate a wider scope of information in their thought, that does not make the thoughts of others any less rational simply because the scope of their information is narrower.
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--James