Not having been raised in a religious home and indoctrinated from an early age, I've often wondered how "otherwise seemingly intelligent people" could be religious? Statistically, very few adults are converted without some major trauma in their life. I spent five years as a fundamentalist Christian. I had to shelve a lot of my doubts and questions to have any comfort level with my new "belief system". The more I studied, read apologetics, and asked questions, the less convinced I became. I have been an Ignostic Agnostic Atheist for seven years or so now.
I still miss the fellowship and promises of a better afterlife on rare occasion, but most of the time, I am glad to not be suffering delusions.
There never seem to be truly open debates on Christianity (or other religions) and I have gotten where I generally just shy away from them as long as people stay out of my face.
One of the best skeptic web sites I found was http://whywontgodhealamputees.com. If you value reason, logic, and reality, it is well worth a good look.
At http://whywontgodhealamputees.com/video10.htm you'll find a video; 10 questions that every intelligent Christian must answer. I have not seen one Xian answer a single one of the questions in an intelligent or convincing manner following the rules of logic (http://www.simplyquality.org/Logic.htm). I'd love to see one or more do so. Most will never even try.
"Fly, be free!" - Mork from Ork