Sentence:  Reiki, much like prayer, is a personal exercise that can easily convert negative <WSD>energy</WSD> into positive <WSD>energy</WSD>. 
Meaning of the word marked with <WSD> tags:  An intangible, modifiable force (often characterized as either 'positive' or 'negative') believed in some New Age religions to emanate from a person, place or thing and which is (or can be) preserved and transferred in human interactions; shared mood or group habit; a vibe, a feeling, an impression. (aura).