Though it's not often, there are times when theistic beliefs are brought up. For instance, our children asked us about the rapture and wanted to know what it was. We gave them a Mormon and Born Again perspective, and did this in as neutral a way as we could. We often shoot for this neutrality because we're curious to see what our children will think on their own. This is not to say we don't offer up our opinions from time to time, but we always wait to see what our children think on their own first. We like to see the wheels spinning and the exercise in critical thinking. In this case one of our sons seemed a bit confused and said, "So, the prince of peace is going to come down and burn everyone that doesn't believe in him?" That's verbatim. He said this recognizing that he didn't believe in Jesus, and to him, he couldn't see how that would be very fair. Our children were equally confused with why people believe in Christianity. We explained to them that it was because Christians feel that everyone that has ever lived in this world, with the exception of Jesus, naturally had, or has had, a little too much evil in them and that evil qualifies them to be punished for eternity. We explained that many believed Jesus was the only one without evil so he was the only one able enough to get into heaven, and since he could get into heaven, he could get others into heaven, but only if they believed in him. Our children could not get past the "everyone is evil part" and thought the story sounded ridiculous after that. They simply know too many people that have rejected Christianity that they think are good people and they don't see why those people would deserve to be punished eternally over a belief, especially when so many different opinions on what people should believe exist. They have learned about the universe and evolution and have realized on their own how those two things contradict most theistic viewpoints. The pattern you're seeing here, is that, on their own, they don't buy into theism, and nobody is telling them they should.