I use the term in a metaphorical way. I don't "believe" in it, or think there is really a spirit apart from the qualities imbued in us by our material body. I think so-called eastern meditation is beneficial to counteracting the effects of culture. Beyond simple relaxation, I think it helps train the brain so that you can realize the true nature of the mind (mind being the subjective functioning of the brain). When we are caught up in day to day worries and problems, we don't see the true picture of reality, how we filter experience through past experience, how the true potential of consciousness is more than we could have guessed.