Atheists are of three kinds.
There is a fourth kind of atheist, not really an atheist at all. He is but a traveller in the Land of No God, and knows that it is but a stage on his journey—and a stage, moreover, not far from the goal. Daath is not on the Tree of Life; and in Daath there is no God as there is in the Sephiroth, for Daath cannot understand unity at all. If he thinks of it, it is only to hate it, as the one thing which he is most certainly not (see Liber 418, 10th Æthyr. I may remark in passing that this book is the best known to me on Advanced Qabalah, and of course it is only intelligibile to Advanced Students).
This atheist, not in-being but in-passing, is a very apt subject for initiation. He has done with the illusions of dogma. From a Knight of the Royal Mystery he has risen to understand with the members of the Sovereign Sanctuary that all is symbolic; all, if you will, the Jugglery of the Magician. He is tired of theories and systems of theology and all such toys; and being weary and anhungered and athirst seeks a seat at the Table of Adepts, and a portion of the Bread of Spiritual Experience, and a draught of the wine of Ecstasy.
'Gems From the Equinox' is my favorite, published by New Falcon Publications. Would that I could afford the entire Equinox, I've only seen the complete set for sale in person once... 'Eight Lectures on Yoga' is another great investment.
I like The Law is For All. It must be read after reading Liber Legis, which is the seminal work on which all that follows is but explanation or illustration. The Law is For All is an explication of Liber Legis. There is a lot to appeal to an atheist in The Law is For All. It appeals to the freethinker, and yet it also presumes a knowledge of mysticism, usually anathema to an atheist.
Now that I think about it, perhaps Magick in Theory and Practice is a better starting point. This anthology of essays and rituals, one of the works in Book Four, went into public domain for a while and was available in an inexpensive edition from Dover. When he wrote the Gnostic Mass, Old Crow included a section called "The Collects," in which he lists a veritable host of famous and infamous -- notorious -- persons who thought for themselves, including the explorer, Sir Richard Burton, who said (Thelemically): "He lives best and dies best who keeps his self-made laws." The Great Beast also put in one of the Borgias, Nietzsche, and leaders of Gnostic sects. I did a who's who of the saints in a magazine piece and just researching the matter took weeks.
I just looked up our copy of Book 4 on Amazon and just about had a coronary! I think we paid $49.95 @ Mountain Books in Michigan many years ago and now the same edition is selling for over $120.00! But yes, Book 4 I would concur, is one of our favorites and we quite enjoyed Magick in Theory and Practice and of course I like the big ol' Golden Dawn doorstop edition as well even though Israel does tend to drone on... ;)
Earlier editions of Crowley works tend to increase in value over the years. You probably can get Book 4 for less used. Do you have the old Weiser ed.? I made a mistake, I think, saying Magick in Theory & Practice was part of Book 4. I think it is a part of a four-part compendium titled Magick. A work like Eight Lectures on Yoga can be of value to the reader even if she is an atheist. I am certainly no expert on Crowley writings, and those I have met were insufferable.
Yeah it's the Weiser ed. 1994 printing and Part III is Magick in Theory and Practice you were correct. Book Four is comprised of Part I Mysticism, Part II Magick (Elementary Theory) and Part III we've already mentioned, Part IV is Thelema - The Law. I'm the one breaking the books up in memory LOL you were on track. I actually had to go get the book out to be sure!
I think I was thinking of his letters to his students, which if memory serves, is Magick Without Tears.
Yes, and probably edited by Regardie. I may still have my copy of the Weiser Book 4.