SEOUL, South Korea -- April 15 is known in North Korea as the "Day of the Sun" in honor of late President Kim Il Sung's 100th birthday.
It's one of the most important dates in recent history for the communist nation.
The 'Eternal President'
Even though he died in 1994, Kim is called the "Eternal President" and is worshipped like a god.
Dressed in their finest, thousands will travel to the capital city of Pyongyang Sunday from across North Korea. They'll march up to the giant statue of Kim and on cue, bow.
"The Korean people will definitely build up this country into a great and powerful nation by 2012, which marks the 100th anniversary of the birth of great leader Kim Il Sung," Pyongyang resident Kim Ho Nam said.
"It makes me miss him even more strongly," Pyongyang resident Pak Hyon Jong added.
As millions of North Koreans celebrate the occasion, millions of Christians in Seoul, South Korea, are praying that revival hits the communist nation.
All week they've been meeting in churches, homes, and small groups to ask God to tear down the walls of oppression in North Korea.
"The people there have suffered for so long, something has to change," one South Korean woman said.
"When you look at the situation in the natural it seems impossible," another woman said. "But with God nothing is impossible. We just need to keep praying."
North's 'Secret Believers'
They've also been praying for North Korea's secret believers. Pastor "Peter" Chung, whose true identity has been concealed for his protection, has family there.
He defected to South Korea several years ago. He's also the first ever North Korean to earn a theology degree.
"I have family and friends I've not seen in years. I cannot imagine what they're enduring," he told CBN News.
Trying to obtain precise figures on the number of Christians in North Korea is extremely difficult.
"Based on data gathered from North Korean defectors and international human rights groups, we estimate there are approximately 30,000 Christians being held in political prison camps and about 10,000 underground believers who are in hiding throughout the country," Lim Chang Ho, a professor at Kosin University in South Korea, told CBN News.
Chung, who travels often to North Korea, has met several of those underground believers. He said the persecution of Christians has intensified since the death of Kim Jong Il.
"We can only pray that God will comfort and protect these believers and hope that one day they will be free to worship like the Christians in South Korea and around the world," he said.
Praying for Revival
As North Koreans gather this Sunday for the historic anniversary, Chung is encouraging Christians worldwide to use the day to pray for God to do the impossible in his homeland.
"People talk about regime change in North Korea. Yes, that may help, but that's not going to ultimately bring change," Chung told CBN News.
"We have to pray for the leadership," he said. "We have to pray for a powerful spiritual revival to sweep across the country."