Caught in a raging Siberian blizzard hours after crossing the frozen Heilongjiang river into the Soviet Union, Zhang Boli thought he was going to die in the snow on Christmas night, 1989.
The former student leader of the Tiananmen pro-democracy movement had been on the run for six months after it was crushed by the military, moving from village to village in remote Heilongjiang , assuming different identities.
As he was about to faint, he remembered something taught to him by a Christian woman who hid him for months - pray. He decided to dedicate his life to God.
The next morning, he was rescued by Russian peasants who found him lying unconscious covered in thick snow. The Soviet Union refused to allow Zhang (pictured) to cross to the West for fear of offending Beijing, but instead allowed him to slip back into Heilongjiang without alerting the mainland authorities.
For the next year-and-a-half, Zhang survived on hunting and fishing, until he eventually made his way to Shenzhen, where he fled to Hong Kong on a speedboat on June 13, 1991. Three days later, he travelled to the United States, where he was granted political asylum.
Today, Zhang is a pastor at the Harvest Christian Chinese Church in Virginia. His days as a student clamouring for democracy at Tiananmen Square seem like a lifetime away.
Although he is barred from returning to China, Zhang has not stopped caring for his country. Chinese people live in a society plagued by corruption, inequality, a moral crisis and lawlessness, Zhang said, and needed Christianity more than ever.
"Christian concepts such as love, tolerance, forgiveness ... are all good for China," he said. "[To me], spreading the gospel is more meaningful than engaging in pro-democracy activities.
"Democratic values are based on concepts such the equality of all people in the eyes of God and their rights and dignity," he said. "I can't see another ideology more suitable for China."
Zhang said many people lost faith in the Communist Party after the June 4 crackdown and feared that if another pro-democracy movement started, "the conflict would likely be more intense because people have bottled up more grievances".
Christianity could play a role in democratisation and help promote social justice, he said. Zhang cited an estimated figure of 80 million protestant Christians on the mainland and said they could be a powerful force in building civil society.
"It can change people's hearts and bring its influence 'like salt and light' in the world," he said, paraphrasing Jesus' words from the Book of Matthew.
"Christianity never talks of toppling regimes, it can only make society better," he said.