The Church of Scientology says that a human is an immortal, spiritual being (thetan) that is resident in a physical body. The thetan has had innumerable past lives and it is observed in advanced Scientology texts that lives preceding the thetan's arrival on Earth were lived in extraterrestrial cultures. Based on case studies at advanced levels, it is predicted that any Scientologist undergoing auditing will eventually come across and recount a common series of events.
According to the Church, founder L. Ron Hubbard's discovery of the thetan places Scientology at the heart of the human quest for meaning, and proves that "its origins are as ancient as religious thought itself." However, Scientology considers that its understanding of the thetan distinguishes it from other religious traditions, especially Judaism and Christianity, in three important ways. First, while many religions fuse the concept of the body and the soul, the thetan (spirit) is separate and independent. Second, unlike the three great world monotheisms, Scientologists believe in past lives and that the thetan has lived through many, perhaps thousands of lifetimes. Third, contrary to Christian concepts of original sin, Scientology holds to the intrinsic goodness of a being and believes that the spiritual essence has lost touch with its nature. "The spirit, then, is not a thing," Hubbard writes. "It is the creator of things."
Scientology describes itself as the study and handling of the spirit in relationship to itself, others, and all of life. Scientologists also believe that people have innate, yet suppressed, power and ability which can be regained if cleared of enforced and unwanted behaviour patterns and discomforts. Scientology is described as "a religion to help people use scientific approaches to self-actualize their full potential." Believers reach their full potential "when they understand themselves in their true relationship to the physical universe and the Supreme Being. " There have been many scholarly studies of Scientology and the books are freely available in bookshops, churches and most libraries.