
Brennan claims to receive intuitive information about her clients during sessions, and to see repetitive patterns in the energy fields of her clients indicating common roots underlying their difficulties. Her first book, Hands of Light: A Guide to Healing Through the Human Energy Field, is considered a "classic" in the field of spiritual healing, with reputedly over one million copies in print in 22 languages. Brennan has a PhD in philosophy from Greenwich University in Australia and DTh in theology from Holos University, both earned in 2001. She developed her own private healing practice in 1977 and then established a training programme to teach others. Brennan also took seminars with and was influenced by Rev. Brennan worked with the Pierrakos, and became a Pathwork Helper and Core Energetics therapist. She was strongly influenced by Eva and John Pierrakos, who founded a system for self-transformation called the Pathwork, drawing on the ideas of Wilhelm Reich and Alexander Lowen. She completed a two–year program in Therapeutic Counselling at the Community of the Whole Person in Washington, D.C., followed by a three-year program in Core Energetics at the Institute for Core Energetics in New York City in 1978 and a five-year program in Spiritual Healership at the Phoenicia Pathwork Center in Phoenicia, New York in 1979. From 1970, she participated in courses at a number of unaccredited institutions, offering courses in the "human energy field". She then went on to spend six years working at NASA's Goddard Space Flight Center. Brennan received a Bachelor of Science degree in Physics in 1962 from the University of Wisconsin–Madison, and two years later received her Masters in Atmospheric Physics from the same institution.
