Freemasonry is not a boy’s club or an occult society. However, some Masons–entire lodges in rare cases–may treat it as such. It is a fraternity with exoteric purposes of self-improvement and benevolence to all, that is, ideally, to be founded on the esoteric goal of acquiring true self-knowledge via introspection. It’s about a man finding his rightful place in this or his world. If you go into the Grand Lodge in London, you’ll see a seat–made of stone I think–on which the Grandmaster sits that has “Know Thyself” engraved on it.
As far as I know, you are never rejected for a specific spiritual belief but rather the lack of one. However, some lodges do accept atheists. In most of the Western World, Masons tend to have a Christian affiliation of some sort but they’re unlikely to be the born-again and evangelical types. The church and other establishments typically resist something different because they want everyone to be like them ( the chief cause of the world’s problems IMO ). However, the days when Masons and the church were bitter enemies are long gone: both have evolved into something that is generally far more open and accepting than it used to be. They might not love each other but they’re not at each other’s throats necessarily.
Most lodges engage in the standard rituals, charity and some social stuff like dinners, open days etc. Go visit a lodge if they hold an open day for the public: most larger lodges do. I’m pretty sure the one in London does. Yes, there are some Masons who are far more inclined towards the introspective or esoteric aspects of Masonry but they don’t seem to be a majority. Many Masons treat it like a boy’s club or general charity but that isn’t what it’s all about.
Nothing juicy necessarily goes on in your average lodge. In fact, people leave the fraternity because some lodges are so fucking boring or old-fashioned. That’s one drawback of the fraternity: they seem rather slow in letting go of their unnecessary traditions, i.e. the stuff that isn’t allegorical with some hidden meaning beneath the symbolism.
Crowley was definitely more esoterically inclined than an average Mason and certainly more flamboyant: he couldn’t be held by their restricted/traditional points of view. He eventually left and formed is own orders that focussed entirely on mystical and occult practices. One thing to note: this is a 5 million strong, worldwide organisation and you’ll have a few arses in there to be sure, so don’t expect a totally hunky dory set up. A family of 5 can be complicated and you can bet Freemasonry has/had/will have issues from time to time.
What spirit operates in Freemasonry? Well, it would be best described as a kind of a Universal Humanism. However, I think the spirit of inquiry and truth is the real active aspect from an individual Mason’s perspective. The name they give to their deity is somewhat impersonal, i.e. GAOTU (Great Architect Of The Universe).
You know, since you’re so drawn to it, just go talk to someone in the lodge. I think the London lodge should be an okay bunch. Check it out. No harm done.