Reiki can never cause harm. Because Reiki is guided by the God-consciousness, it can never do harm. It always knows what a person needs and will adjust itself to create the effect that is appropriate for them. One never need worry about whether to give Reiki or not. It is always helpful.
In addition, because the practitioner does not direct the healing and does not decide what to work on, or what to heal, the practitioner is not in danger of taking on the karma of the client. Because the practitioner is not doing the healing, it is also much easier for the ego to stay out of the way and allow the presence of God to clearly shine through.
~Reiki: The Healing Touch