IS hostage Kayla Mueller's faith was so bold, so raw, so refreshing that 20/20 investigated her Christianity for an episode on the modern-day Stephen. A fellow-hostage (from Doctors without Borders) said, ‘She was always considerate of others, even though she herself was in a very difficult situation. She was always concerned for other prisoners. She never stopped caring for others.’ Kayla was kidnapped by IS in 2013. They told her parents she was alive in 2014, but then airstrikes hit. Her death was announced in 2015. Despite rape, torture and further unthinkable abuse, Mueller's fellow hostages say she refused to deny Christ and even witnessed to Islamic State executioner, Jihadi John. The 20/20 episode premièred last week and is available at