Tens of millions of Christians live in China today, many of them leading double lives or in hiding from a government that relentlessly persecutes them. Bob Fu, whom the Wall Street Journal called "The pastor of China's underground railroad," is fighting to protect his fellow believers from persecution, imprisonment, and even death. God's Double Agent is his fascinating and riveting story.

Bob Fu is indeed God's double agent. By day Fu worked as a full-time lecturer in a communist school; by night he pastored a house church and led an underground Bible school. This...