You can think of the Hermetic order Golden Dawn as the beginnings of spirituality. Many modern day religions, and also systems within witchcraft have been adopted from this order. The Hermetic Order of the Golden Dawn was founded in Britain in the late 19th century by Freemasons. Although this was founded by Freemasons, men and women were admitted on an equal basis.
If you ever heard of Aleister Crowley he was a member of this order along with other cultural figures. Aleister Crowley probably authored some of the books you’ve been studying in your esoteric Journey. He also not too common religion called Thelema, what some may consider more of a religious philosophy.
There are many texts that reveal some of the Golden Dawn’s teachings and there is even a tarot deck meant for these studies. One of the most common published books that goes into the teachings of the Golden Dawn is Modern Magick by Donald Michael Kraig. He goes into depth about Golden Dawn and also about some of his personal experiences with the occult.
You can read more on this order on Wikipedia.