"Theorists have not been at a loss to explain; but they differ."
The words in quotes are attributed to Gerald Yorke by way of Kathleen Raine's 1969 article Yeats, the Tarot, and the Golden Dawn. So far as I know, Raine's article is the only source for this quote, which she states is from a letter written by Yorke.
Here is the full text of the footnote from Raine's paper containing the quote:
On the question of the degree to which the Society was Christian the experts differ. Mr. Geoffrey Watkins believes that it was strongly so from the first. Mr. Gerald Yorke that A.E. Waite who rewrote the ritual extensively when he broke away from the original Order, was mainly responsible for the Christianization. "Where the G.D. called itself a Hermetic Order, Waite called his version a Roscirucian Order, and the Rosicrucians were always more Christian than the Hermetists. In the original G.D. the Christianized Rosicrucian material did not come until the 5=6 degree in the Inner Order. Here for the first time you find the Calvary cross, but with a rose on it instead of the figure of Christian." This quote from a letter fro Mr Yorke; who further writes: "Now Hermetic Orders as such are only Christian in that they include some Christianity but do not stress it. Rosicrucian orders on the other hand are primarily Christian but draw on other pre-Christian sources. In other words the Hermetists always try to become God in his anthropomorphic or in some instances theriomorphic form. They inflame themselves with prayer until they become Adonai the Lord ... whereas the Christian approached God the Father through Christ (Adonai) but never tried to become Christ, only to become as Christ. Thus the Hermetic (or pagan) approach is as Adonai to order the averse hierarchy about, the Roscirucian approach is to order them about through the grace of Christ or through the power of His name ... Now the G.D. used the pagan formule, the Hermetic formulae and pre- or non-Christian names of power, take from the Hebrew, Greek, Coptic, Egyptian and Chaldean sources. The Rosicrucian substitutes names from the Christian system, from the Christian Trinity, etc. Both systems combine when it comes to the archangels Gabriel, Uriel, Michael and Raphael. They also agree on the Cherubim, Seraphim, etc. The G.D. way of becoming the god is the dangerous one, as it leads at once to inflated ego, witness Mathers and Crowley, et al. The occult orders are full mostly of people who are for the time being in revolt against or not at home with Christianity. When they find that the occult, Hermetic pre-Christian way of doing things at its best is no better than the Christian way, they often find their final home back in Christianity or in Islam, Buddhism or Hinduism. For the major religions are major because they have stood the test of time better. Thus my conclusion is that the Hermetic way of the Golden Dawn is primarily Hermetic and not Christian, since it is reverting to pre-Christian methods and attitudes, but some of the members will have done it all in a Christian way way. I am fairly certain that these were the minority at any given moment and seldom remained in the Order all their lives. But this of course is a personal opinion."
I quote this valuable opinion of Mr. Yorke for the light it throws on the impoderables of an ambience, and emphasis within an Order at best ambiguous. Mr. Watkins's view of the predominance of the Christian emphasis may be founded on the fact that two of the founder-members (not Mathers) were members of the English Rosicrucian Order. As regards Yeats, we must be left wondering, as Thomas Butts wondered about Blake, whether his angels were black, white, or gray; but the colour of the angels themselves may perhaps lie in the eye of the beholder. In any case, from a Catholic point of view the Oder of the G.D. would stand condemned if only on the grounds of the vow of secrecy imposed upon its members.
In my own (decidely inexpert) opinion, the Golden Dawn was so unstable and short-lived precisely because its members included partisans of both camps, as well as others who wavered between the two. And the long term influence of the G. D. might also be due to this chimeric quality, which allows would-be adepts the freedom to project their own attitudes concerning the cult of Jebus onto the theological Rorschach test that was the original Golden Dawn.