As I read more and I got into philosophy and met a lot of friends who weren't Christians, it became difficult for me to sustain the belief structure in the supernatural.

There are very few places in the world where you have to learn a language with no language in common. It's called a monolingual field situation.

It's wrong to try and convert tribal societies. What should the empirical evidence for religion be? It should produce peaceful, strong, secure people who are right with God and right with the world. I don't see that evidence very often.

One of the saddest things I've seen in Amazonian cultures is people who were self-sufficient and happy that now think of themselves as poor and become dissatisfied with their lives. What worries me is outsiders trying to impose their values and materialism on the Piraha.