The term "evangelical" is taken from the word evangelize, but it turns out that most who claim to be the former don't really do the latter.
Veteran pollster George Barna finds that just 25 percent of self-described Christians even think that it's part of their job to share their faith.
Among those who say they're born again, that number is still below 50 percent.
An author and long-time researcher, Barna currently leads the American Culture and Faith Institute, which tracks religious faith in the United States.
"People who have that kind of personal relationship with Christ, and depend upon him and him alone for their salvation," says Barna "are less and less willing to share that kind of gift with other people."
Evangelism is a common tenet of the Christian faith, since the belief is "lost" people are unaware of the message of gospel unless they are told.
Penn Jillette, the Las Vegas magician who is an atheist, famously suggested that he doesn't respect Christians who don't evangelize, when he was approached by a man after a show and handed a Gideon Bible.
"How much do you have to hate somebody to not proselytize?" Jillette asked in a video (see below) from 2009. "How much do you have to hate somebody to believe that everlasting life is possible and not tell them that?"
Even among those that are willing to share the gospel with others, Barna's research found, nine out of ten share things that are not grounded in scripture - such as people are basically good, it doesn't matter what you believe as long as you really believe it, or you can be saved by doing good deeds.
"It really becomes kind of a mish-mash of ideas from the Bible but also from pop-culture, and from other faiths," Barna observes. "So that when people are receiving the gospel, it may have nothing to do with what Jesus' life, death and resurrection actually was all about.
What about the idea of being a "silent witness" for the Christian faith?
Most born-again adults believe they're engaging in "lifestyle evangelism," says Barna.
"But then when we studied the lifestyles of those people," he says, "what we found was that there really wasn't that much difference between those individuals and the people that they allegedly hoped to influence."
The first step in reengaging with real evangelism, he advises, would be to actually get out in the world and mingle with the lost souls around us.