Article: Scientologists consider their religion to be a practical philosophy or self-actualization method, more so than a religion in the strictest sense of the word. As a religion, Scientology is relatively new, extending from writer L. Ron Hubbard’s mid-century method of self-improvement via past-life exploration and auditing, called dianetics.  There is a spiritual mythology related to Scientology which can sound a little sci-fi to the uninitiated, but Scientology itself is about the practice more than the belief in the system. Scientologists do believe that the inner self is a "cosmic" being, something that lives beyond the body and which needs to be properly maintained when in your care. Applying the principles of the Tone Scale and Dynamics to your life is thought to help eliminate the reliance of modern society on mood-altering substances and other primarily commercial  methods of “self improvement.” More than perhaps any other contemporary religion, Scientology is widely criticized and mocked in pop culture, for a variety of reasons. Scientology calls itself a religion, but it is often accused of being a cult, a pseudo-religion, or a pyramid scheme. If you're planning to join Scientology, it's crucial to learn about it from a variety of sources rather than relying on official statements from Scientology only. According to Scientology, the organization does not make it impossible to "leave" the church, nor do they outlaw the use of certain medications. However, Scientology has been accused of behaving like a totalitarian system which disconnects its members from friends, colleagues, or family members deemed to be antagonistic towards Scientology. Furthermore, Scientology does strongly oppose the medical specialties of psychiatry and psychology. If you choose to explore Scientology, there's a lot you should expect to learn and study. Some of the vocabulary can be momentarily disorienting, so having some idea of what to expect when you're first exploring can help you negotiate the somewhat complicated waters of Scientology.   Dianetics is the original method invented by Hubbard as a self-improvement method, regarding a mind-body connection. The goal of dianetics is to get your "reactive mind" out of the way, leading to a happier, more fulfilled state of being.  Thetans are believed to be immortal beings, insubstantial in nature, that rule your body. Scientologists believe Thetans create life and exist independent of our bodies beyond death. This is the Scientologist conception of the human soul, essentially. Practicing Scientology and finding practical benefit from it doesn't require that you "believe" in Thetans in the strictest sense of the word. It would be impossible to give an accurate primer on the wide body of thought that represents Scientology in a few hundred words. The church is known for the easy access to and volume of reading materials associated with it, so get in touch with the Church of Scientology, via their website and request literature. It’s generally free of cost.   Scientology: A Religious Philosophy by L. Ron Hubbard outlines the basic tenets of Scientology, though more easily digestible volumes are frequently produced by the church for more easy consumption. In general, if you request materials, you’ll likely be inundated with more boxes than you know what to do with. This is a promotional tactic used by the church to spread the word. Be forewarned and expect lots of books.

What is a summary?
Understand what Scientology is. Inform yourself. Learn what to expect from Scientology. Request introductory literature from the church.