According to what we find in the New Testament… well, nothing, directly.
We often hear a lot about Yoga these days, and how the spiritual side of it can affect us negatively. A friend of mine recently forwarded me an email from someone who seemed to know a lot more about Yoga than most of us, and was able to describe exactly how the spirit of Yoga could enter one’s body, if we are foolish enough to give it the chance to do so. Scary stuff indeed.