But in Christianity you WANT to invite the Holy Spirit into you, or into your life. Imo that's the "good" voice in your head that guides you to make good decisions, or to show kindness to people, etc. And that feeling when you KNOW you've just done something good, that's the Holy Spirit as well. When Jesus left the Earth, then the Holy Spirit came here, to guide us. Before then, the Holy Spirit wasn't here. A lot of people don't realize that.
All these other things like wicca, Scientology, reiki, etc. are opening you up for "bad" energies, or spirits. And a lot of them seem harmless at first, or even good. And some of them can seemingly do some amazing things....that's the hook. But research it and you'll see that they're not good in the long run, and a lot of people end up messed up from it.
Just my 2 cents.