There can be a lot of doubt about Gurdjieff being an adept and I have expressed various doubts about his character and relations with women as well as certain political involvements.
The larger issue of abuse by occultists also exists. He met and probably bested Crowley at Crowley's low point and on his own turf. Crowley had become a serious druggie and his powers are less than what I would consider righteous at any point, even when he headed up the Hermetic Order of the Golden Dawn which included powerful people from all disciplines and inner sanctums of those who will never appear on their public membership. They bragged about having achieved higher numbered levels of knowledge beyond the 99 or most puissant you will hear associated with Crowley. I do not know enough about 137 or other numbers and I am not an expert in Gematria. I would like to think Gurdjieff never bought into demons although his Beelzebub and life was on the edge of what humans create which people call demons.
I see Gurdjieff as a man who became a gifted savant and teacher of Righteous enlightenment and Crowley never did.
Here is a little Thelema from a website addressing some of the Crowleyan crap. Remember there have been good people like Robert Anton Wilson who benefitted from Thelema and many great people of worldwide acclaim who hung with him in the Inner Sanctums at the Hermetic Order of the Golden Dawn. His personal secretary at that time was Israel Regardie and Regardie's courses are perhaps the best education you can get. There is no taint on Yeats I have found who we have addresses in many threads including the thread on the Golden Dawn and him. But 'be ye wise' and careful among those who seek power and know if you allow fear to be your guide they will have a grip or entryway to places you should not let them go.
https://holythelemicchurch.wordpress.com/ I quote a little from it, but I also say it was his way of duping people - and himself. That does not mean you cannot learn a great deal from Crowley.
"“Do what thou wilt shall be the whole of the Law.”
1. Here you find terms such as “church”; “gods”; “magick”; “saints”; “power”; “worship”; “devotion”; and so on. Here nothing is as it seems.
2. Here divine genius may be realized within; and achieving that, one may expand the mind without, to the realization of the infinite, via the union of Samadhi.
3. Here is atheistic Gnosis of Apotheosis.
4. Here all religious approaches may be modified to fit an overarching Thelemic Law designed to serve the interests of woman & man, not an idealistic, immaterial god.
5. Here saints are those who have realized some measure of genius, be it artful, musical, scientific, or expressive — whatever have you.
6. Here worship-like practices are utilized neither for propitiation nor for superstitious aims, but to open various pathways of the mind for (a) the realization of hidden potential inherent in all, and (b) the transmission of praeterhuman awareness on a cosmic level through that open channel of greater self-awareness within.
7. Here magick is not the bewitching of cattle but the stirring of Supernal Potential, and vitalization of creativity as well as realization of greater self-empowerment.
8. Here sacraments are not impossible elements of spiritual contrition, but rather devices of celebration of the natural human/animal condition.
9. Here is no place for outrageous spiritual superstitions.
10. Here ideas like sacrifice are abhorred as blasphemous self-abnegation. Here happiness, bliss, merriment, freedom, promiscuous indulgence, are virtues.
11. Here is no one way. Here is no authority. Welcome to the Holy Thelemic Church.
“Love is the law, love under will.”"