This is their own website; might be a good place to start your research.
A good link, bouncer. You might also start at the fountain source:
And once all of you have become experts in the 'Great Mysteries of Thelema', yes, once all of you have become Illuminates in the God of Force and Fire Horus, and once all of you have become assured that it is Christianity's last hour,
You might just understand, when you reach to top of Mon Salvat, when you believe that the Enemy has seized the Grail for itself,
That a Christian now has both the Grail and the Lance. Yes, indeed, a Christian nows reigns supreme over all Illumniati, Thelemites, Satanists, various and sundry antichrists, and everything else that exalts itself against the knowledge of Christ.
And the delicious thing about it is...
It is based on hard fact. No jokes, no illusions.
Do you think I am flying high on an ego trip?
Oh, no. I assure you it has nothing to do with such triffles. It's about so much more.
This isn't for a show, this one's for the whole thing.
And I play for keeps.