What do you have to give these days to launch a successful word-of-mouth campaign? Apparently, just your soul. According to a study released in early July by Ventura, Calif.-based Barna Research Group, 1 in 3 Christians (29 percent) have shared their religious beliefs with a non-Christian in the past year in hopes that they might â€œaccept Jesus Christ as their savior.â€? The telephone survey of 6,038 adults, conducted between January 2000 and June 2001, reveals that the Christian denominations whose members are most active proselytizers are: Pentecostal (61 percent), Assembly of God, (61 percent), Baptist (43 percent) and Church of Christ (35 percent). Those least likely to come a knocking are Catholics (10 percent) and Episcopalians (14 percent).