The late British journalist Malcolm Muggeridge wrote in Christ and the Media that "the media have provided the devil with the greatest brainwashing operation since Adam and Eve. … history will see advertising as one of the real evils of our time."

Tim Finley has seen the sinister side of advertising. A former national advertising and direct-marketing expert, Finley saw the media used to sell everything from medically dangerous weight-loss programs to shady investment schemes. By his own admission, he marketed products that emptied souls.

Since then, Finley believes he has found a way to redeem this medium—using its power to sell a message that brings life to the lost.

Finley and the organization he founded in 1998, Mars Hill Media (MHM), have reached a potential reader audience of 45 million. Producing shrewdly conceived full-page ads in major newspapers like the Los Angeles Times and USA Today, MHM seeks to engage Americans creatively and alter their perceptions of Christianity.

During a 15-year advertising career in the secular marketplace, Finley saw both the positive and negative influences of advertising. After being graduated from the University of Minnesota in 1983, he worked for several ad agencies, joining a small Minneapolis agency in 1990 that he and several partners built to national prominence. Within seven years, the firm grew from 7 to 80 employees and was billing over $100 million per year.

Finley became a national expert and sought-after speaker on direct-marketing strategies. Although he was a committed believer, a creeping carnality was beginning to infect him. Amid increasing financial rewards, his soul, in his words, was "beginning to be eroded."

Shortly before speaking ...