The Church of Scientology is 50 years old this year, having survived its skeptics and detractors, an investigation by the Internal Revenue Service and John Travolta's box-office flop, "Battlefield Earth," based on a science fiction novel by the church's founder L. Ron Hubbard.

The church's 50th anniversary makes it a young religion as far as religions go but also attests to its staying power.

According to Scientology headquarters in Los Angeles, the church now claims more than 8 million members in 159 countries. The current president of the Church of Scientology International is a former Utahn, Heber C. Jentzsch, who grew up as a member of The Church of Jesus Christ of Latter-day Saints and attended the University of Utah. As he once explained to TV interviewer Larry King, Scientology provided him with answers to questions such as "Who am I? What am I doing here? What are these other people doing here?"

The Salt Lake Church of Scientology numbers between 200 and 300 parishioners, according to lay minister the Rev. Phillip Parke. It operates out of a two-story office building in Sugar House that includes "auditing" rooms, a sauna and a small chapel where services are held on Sunday mornings. Attending a Sunday service for the first time provides only a tiny glimpse of the church's complex philosophy.

The service begins with a reading of the "Creed of the Church of Scientology," written by Hubbard, a short treatise on integrity, written by Hubbard, and a sermon from a large, gold leaf copy of "The Background, Ministry, Ceremonies and Sermons of the Scientology Religion," also written by Hubbard. The founder of Scientology was a prolific man. Before he died in 1986, at age 74, he had written not only more than 200 science fiction novels but 31 church-related books, including "The Road to Truth" and "All About Radiation."

After the sermon comes the heart of the Sunday service — "group processing" — which on a recent morning included the following exercise, also written by Hubbard. Minister Judy Steed, a cheerful, intense woman, instructed us to find the floor, to locate the chair we are sitting in, to observe the front wall, the side walls and the wall behind us. We did this again and again, finding the floor, the chair, the walls, the ceiling, observing the distance between ourselves and the ceiling and walls.

"Now," the Rev. Steed said, "find the distance between yourself and your eyeballs."

The Rev. Steed never drew any conclusions for us, but the implication was that if we can separate ourselves from our eyeballs, in the same way we can separate ourselves from the material world around us, we can realize that we are not our bodies but something else. If this sounds a lot like the mind-body dualism philosopher Rene Descartes postulated 350 years ago, Hubbard was quick to point out that Scientology is the one religion to have figured out the real truth: man's real self is neither body nor mind but spirit. And if that sounds a lot like what other religions might call a soul,