You're right- recent polls found that approximately 70% of the US population considers themself to be "Christian." Yet, if this were true, we would not have the problems we have today. People are confused. They are seeking after empty things in life, and are not really following Christ. This is why so many horrible things in history were done by so called "Christians." If they truely knew God, they would not seek to destroy or harm, but would seek to do as Christ calls us to- 'Love your neighbor, forgive others, seek peace.'