Son of the underground: the story of Isaac Liu, son of "The heavenly man"

In the months before Isaac's birth, his father was in prison once again.

His mother was forced into having an abortion, though seven months pregnant, because she was carrying the child of an enemy of the state.

After desperate prayer, the night before she was due to go into hospital for the operation, she miraculously gave birth.

Isaac met his father for the first time at the age of four.

Brother Yun was constantly on the run, and his mother had to work to feed the family, so his grandmother cared for him.

One day his mother was also arrested. Isaac and his sister were swiftly taken to another town by local Christians, where they registered at a school under false names.

The family finally managed to flee to Burma, Thailand and ultimately Germany.

As he grew up, what should Isaac do? Isaac's mother had prayed that God would not call her son to be an evangelist - but his father had dedicated him to God.

Isaac, now in his twenties, has embraced the call to be a pastor.