South Korea is one of the great success stories of the past 30 years, moving from military dictatorship to a strong democracy and economy. 

Last year, it weathered a serious test when the former president tried to declare martial law. He’s since been removed. 

But South Korea’s also the home of a thriving number of troubling religious cults – some of them exported to Australia. 

Professor Tark Ji-il of Busan Presbyterian University understands this threat better than most. Not only is he a world-renowned expert, his family’s been affected in a tragic way. 

He was in Australia recently, sharing his story.