It's not a song by REM. Sometimes, for one reason or another, people begin to question their religion, challenge it and, occasionally, lose it altogether. This documentary hears from those who have taken the decision to forsake their religion, and from faith leaders who discuss what challenges religion faces today. With contributions from Father Keith Baltrop , Farooq Siddique and Rabbi Lionel Blue. Producers Sara Conkey and Nicola Humphries