academically smart or common sense/logic?
There are plenty smart religious people. They just don't talk about their beliefs to you, because they know better.
I remember the smartest teacher at my high school, chemistry, no one really liked the guy as a teacher but he was smart as fuck, knew everything. Someone asked him one time if he believed in god.. he replied, "I look forward to using my Golden chemistry set in the sky."
(ps, i'm agnostic, i'm just playing devil's advocate)