The Holy Guardian Angel
In Ritual Magick, The Holy Guardian Angel or HGA represents one's higher genius; divine self, the Spark of God, which is the essence of every man and woman. The phrase comes from the fourteenth century grimoire; The Sacred Magick of Abramelin the Mage, and is employed in Thelema, where it is considered the central and essential work of all operations.
"It should never be forgotten for a single moment that the central and essential work of the Magickian is the attainment of the Knowledge and Conversation of the Holy Guardian Angel. Once he has achieved this he must of course be left entirely in the hands of that Angel, who can be invariably and inevitably relied upon to lead him to the further great step..."
Even though the HGA is, in a sense, the "higher self", it is often experienced as a separate being, independent from the adept. In Thelema, the single most important goal is to consciously connect with one's Holy Guardian Angel, by doing so, the Magickian becomes fully aware of his own True Will.