Why is it that a lot of Christians don't think for themselves?

I am a Buddhist, and I believe in using my mind and deciding what to believe. In almost ever single religious question posted some idiot has to chime in with "Jesus will save you!", or just quote some page in the bible, rather than taking the time to read and think about the question. One of the things that first made me interested in the philosophy of Buddhism is the idea that it could be wrong, so you need to work out what you believe on your own. What's wrong with that?