The role of healing
There are many unseen factors present when a person asks for a healing. Some people feel they need to keep their illness in order to receive love or attention. In order to give love, others may need to have the role of taking care of an invalid or sick person.
A healer or medicine person/practitioner is only a conduit for healing. The "healer" has to put aside any personal need to be successful, coming from a pure heart and allowing the Universe/creator to do the work. The desire of the sick person to get well has to be present, along with that person's willingness to let go of whatever created the illness, and let go of the hopelessness, therefore being willing to accept and receive the healing.
NO healing is ever a failure. At some level, the person WILL be healed.