Reiki is not a religion, nor new age

"Though Reiki may be considered spiritual in nature, it is not a religion. Neither is it a new age practice or cult. There is nothing you must believe in order to learn and use Reiki. In fact, Reiki works whether you believe in it or not.

Reiki has been used by practioners of Christianity, Buddhism, Shintoism, Hinduism, Islam, and others. It is a spiritual practice which compliments any faith as a "hands on" healing practice.
While Reiki is not tied to any religion, Dr. Usui recommended that a person live in a way that promotes harmony in the body, mind and spirit. The Reiki ideals, listed below, are universally compatible with virtually all cultures and religious beliefs.

If you are Christian, there is an excellent website at http://www.christianreiki.com/."
source http://reikitexas.com/pages/reiki/reiki_religion.php
"While Reiki is spiritual in nature, it is not a religion. It has no dogma, and there is nothing you must believe in order to learn and use Reiki. In fact, Reiki is not dependent on belief at all and will work whether you believe in it or not. Because Reiki comes from God, Goddess, All That Is, many people find that using Reiki puts them more in touch with the experience of their religion or spiritual tradition rather than having only an intellectual concept of it."
source http://www.reiki-light.org/reiki.html