The Hermetic Order of the Golden Dawn (or, more commonly, the Golden Dawn) was a magical order active in Great Britain during the late 19th and early 20th centuries, which practiced theurgy and spiritual development. It has been one of the largest single influences on 20th-century Western occultism.
There is no doubt that some of the men and women who received Golden Dawn initiation found the Order's teachings and its syncretistic approach little to their taste.... Arthur Machen seems to have eventually come to the conclusion that the Golden Dawn was no more than a bad joke....
From the introduction of Astral Projection, Ritual Magic, and Alchemy: Golden Dawn Material by S.L. MacGregor Mathers and Others - Edited and Introduced by Francis King (book form only)
The Golden Dawn, the prototypical "modern occult" movement, is not a bad joke, but an evil joke. Upon first perusal, I noted the same pattern I saw in Wicca: a core of Satanists plying their "religion" by playing head-games with the outer circles consisting of misguided truth-seekers. It's actually a general-purpose front for organized Satanism, so you might be able to imagine more ways they can use it than I can.
There appears to be a connection between the founders of the GD and the Ripper murders, which occurred at about the same time the GD was founded. These murders actually symbolized the "dawning" of the age of Satan, a.k.a. The  New  Age [13, total: 88] - see my essays on the Ripper case.
If you're looking for truthful, detailed information about the nature of the spiritual realms, a good place to start is with one of Rudolf Steiner's introductory books. Another good introductory work is Rudolf Steiner: An Introduction to his Spiritual World-View, Anthroposophy by Roy Wilkerson, which is also on-line. (The "new age" mentioned in the book is the Age of Light, i.e. the end of the Kali Yuga. The New Age is partly an attempt to sow disinformation at this time, when people are becoming curious about the spiritual world.)
These "occult movements" not coincidentally arose in Great Britain at about the same time as Christian Literalism, i.e. fundamentalism. Not long afterward, along came Dirty Bertie Russell and his sidekick H.G. Wells, who came up with their Open Conspiracy, which was concerned with devising quasi-religious movements designed to transfer people's loyalty to the British Empire in the guise of a grass-roots "conspiracy." It's actually quite slick, and disguised as the work of an average mind who couldn't pull the wool over our eyes. EIR published some great articles on this, including The`No-Soul' Gang Behind Reverend Moon's Gnostic Sex Cult (which touches upon Scientology as a "CIA front") and The CCF and the God of Thunder Cult. As usual, they don't just try to analyze the work - they get inside the minds of the writers to expose their motives.