Question for Christians?

OK I know this has been asked a million times, but do you not worry that your faith is largely a result of your geographical location and the culture that you grew up in? If you were brought up in Afghanistan you would probably feel equally strongly about Islam. I am not religious, but if I was I would have no idea which one to pick, I would not want to just go for the dominant one in my culture, there would be no way of knowing which is right.