They see humanism not as a belief system on a par with religion but as an opinion on a par with a political policy.
Now, the converts are so thoroughly immersed in the belief system that they are prepared to engage in street battles.
Traveling "outside" of your body is a phenomenon and belief system that is very wide in scope, with numerous theories and beliefs that attempt to explain it.
Since there's no scientifically proven approach to inducing the experience, the technique that practitioners teach depends heavily upon both the teacher's belief system as well as his or her personal experiences.