Christians can't be serious about ending human trafficking and tackling adult content if they're watching 'Game of Thrones' at the same time, evangelist Christine Caine has suggested.

The popular Christian speaker and writer told the Heaven Come conference in Los Angeles last week that human trafficking could be stopped "overnight" if people stopped watching adult content. 

She also suggested that watching the hit HBO drama Game of Thrones was making it harder to put a stop to human trafficking. 

"I'll tell you how to stop human trafficking, sex trafficking overnight: If people stop watching p*rn. ... Just stop it," she said, according to Fox News.

In a dig at Christians watching the show to be "culturally relevant", she continued, "Here I am trying to put traffickers in jail and you're watching 'Game of Thrones'.

"How's that going to work with a trafficker?"

Caine heads up the international anti-trafficking ministry, A21, which campaigns globally for an end to trafficking and provides support for victims. 

She continued by saying that adult content had a human cost.

"Nothing is free," she said. "P*rn costs somebody."

The warning from Caine follows a study by Gallup last year which found that nearly half of Americans (43 per cent) believe that watching adult content is "morally acceptable", up 7 percentage points from 2011.

She challenged Christians to surrender in all areas of their life, including what they watch on TV. 

"The issue is not whether you are going to die, 100 percent we're all going to die," she said.

"The issue is will you live the life God put you on this Earth to live. Will you step up into your God-given purpose and your God-given destiny and stop playing it safe, and stop living small, and start believing your God is huge and He's able to do so much more than you give him credit for?"