North Korea is known as one of the most dangerous places on earth to be a Christian.
Choi Jeong-hun is a former member of the North Korean military but defected in December of 2016.
He is currently visiting the United States for what's known as the North Korean Freedom Week, an event held each year for the liberation and free unification of North Koreans.
"I come from North Korea and China border area in Yangang Province," Jeong-hun told CBN News via a translator. "In 1988, I was enlisted to the North Korean military. In '94 I was in Mirim military academy. In 1997, I became a lieutenant."
Jeong-hun is also a Christian.
As a member of the North Korean military, he shared how he had witnessed the execution of high-ranking military officials at the hands of Kim Jong Un's brutal regime.
"If you criticize them or these kind people, those who were not compliant, regardless of who they are, they are getting execution or they get harshly penalized," said Jeong-hun.
He went on to say, "For example, just like Jang Song-thaek, who was his uncle, he was using a machine gun to kill his uncle. In North Korea, only the direction of Kim Jong Un, they regard it as this is the order that comes from god. Therefore, so if you are not compliant to his directives or if you criticized them, then there is merciless - they go to concentration camps or were executed. I have seen firsthand and I have also seen all these people who experienced this."
Jeong-hun also explained the false religious beliefs of the North Korean dictator.
"Kim Jong Un has his own sort of religion and he cripples the people mentally in North Korea," he said. "The people who lived as a Christian, when Kim Jong Un, when he took the leadership of North Korea, they were mostly executed."
He added that many Christians who escaped execution, went on to spread the gospel, including himself.
"Me, after I defected, to the North Korean people I am showing them that Kim Jong Il, Kim Jong Un, they are not gods and to show them there is a real God and also to renew the things that they know in North Korea that these are wrong."
Jeong-hun arrived in South Korea in 2006 and now works to secretly spread the gospel of Jesus Christ and the word of God to believers inside North Korea via flash drives, memory sticks and other technology.
Possessing a Bible in North Korea could get you 15 years of hard labor in a prison camp, or worse.
Yet Jeong-hun says the mission must go on.
"We are spreading them inside North Korea," said Jeong-hun.