The two fundamentalist religions I am most familiar with are Islam and Jehovah's Witnesses. In both, believers are strongly encouraged to hang out only with fellow believers. You are told to treat outsiders fairly, but they are dangerous because they may damage your fragile belief.

I was raised as an atheist. I was very curious about believers. How could otherwise sane people believe such nonsense? I tried to find out by sneaking out to churches (my mother would have been horrified), and interviewing people. I finally decided they had no clue why they believed this stuff, they just did. Their notion of what a god was very ill-defined, nothing coherent. Today my exploring would not even require sneaking out. My keyboard would be all I needed.

The descriptions of the universe I read in science grab and shake me with awe and wonder. Only once has anything religious come close. It was seeing a mask of the god Minerva Sulis in the Roman Baths museum in Bath England. In general religions are so pedestrian and kitsch. Islam is more impressive than Christianity, but none come close to Sagan.

How ya gonna hold 'em down on the farm, after they've seen Paree?