It's mentioned about seven times in the Bible. But it's a lot different than what religion actually is. When the Bible talked about religion, most of the time, it would talk about beliefs that were bad and beliefs that didn't really help do anything at all. It doesn't actually mean that Christianity isn't a religion; it is. It's just saying that for a while men have been doing what made them feel better and now they need to worry about what makes others feel better.