Many great world religions have both inner and outer teachings. For example, Judaism, as the outer teaching, has Kaballa as its inner teaching. Islam as an outer teaching, has Sufism as its inner teaching. Esoteric Christianity, sometimes called Mystical Christianity, is the inner teaching of Christianity. A Mystic / Esoteric Christian is one who seeks awareness with Christ through personal experience rather than through dogma and commandments, and also acknowledges ageless wisdom teachings.
http://en.wikipedia.org/wiki/Esoteric_Christianity
Esoteric Christianity
The Cornerstone of Esoteric Christianity
Esoteric Christianity or The Lesser Mysteries by Annie Besant
Fourth Way