Robert Schuller, who began his Southern California ministry by preaching from the roof of a leased drive-in motion picture theater 39 years ago, has returned to a cinematic setting in search of converts.

Schuller, pastor of the 10,000-member Crystal Cathedral in Garden Grove, is being seen in 55-minute, Sunday-morning segments on screen rather than in front of it. The screenings are fused broadcasts of his one-hour Hour of Power, seen on 164 stations in the United States.

"We are the first ministry in history that will produce a movie of a church service every Sunday," says Schuller, 68. An altar call is given at the end of each showing, with local church volunteers aiding with followup. A social hour in theater lobbies follows the film.

Test marketing began in 30 cities around the country last month, as well as in Amsterdam, Frankfurt, Melbourne, and Zurich. The screenings are free, with no solicitation for funds.

A European "superchannel" that had carried Hour of Power now refuses to sell air time to religious broadcasters. Schuller also has been forced off the air in Russia, where his weekly viewership numbered 15 million. "We had to find another way to deliver the show," says Schuller, a Reformed Church in America pastor.

In this country, Schuller sees the plan as a new evangelistic technique. "Unchurched people who wouldn't dare step into a church will step into the shopping center and the mall to meet Jesus Christ."

Schuller is noted for his possibility-thinking philosophy - he hopes to be in 2,000 theaters in two years - and for the elaborate Crystal Cathedral, which has an annual budget of $45 million. Hour of Power, which started in 1970, is the world's single most-watched church service, with more than 20 million regular ...