Just my own summary:
1. David Wood goes into some depth about his testimony or conversion with Eric Metaxas. It starts at approximately 32:30 with Wood meeting another inmate named Randy who was a Christian. Wood saw Randy always sitting in his bunk reading his Bible. Randy wouldn't do anything the other inmates were doing.
2. One day Wood told Randy he was only reading the Bible because Randy was born in the US. If Randy had been born in China, then he'd be Buddhist. If India, Hindu. If Saudi Arabia, Muslim. Wood also told Randy "people like you believe whatever you're told to believe". Wood had the same idea of Christianity that he had of objective morality - that it's just a false belief that people are told by others, which they accept, because they don't know how to think for themselves. I guess Wood's idea is that Randy is a sheep. Like everyone else. Except for Wood himself.
3. However, Randy was the first Christian to put up a fight against Wood and argue back against Wood. Randy challenged Wood. The most "annoying" thing for Wood was that Randy would constantly question everything Wood himself believed: "Where did you get your idea then?" And Wood couldn't respond to Randy. Other than with silence.