If barbaric faith means fully alive and totally sold out, Liddell and Woolman fit the bill as well as any I've ever come across.
The opening speaker is Chuck Mylander, the president of Evangelical Friends Missions. His son, Kirk, was across the wall from me my frosh year at George Fox University. Chuck set me up by quoting from Isaiah: "Though your sins be as scarlet, they shall be white as snow. Though they be red as crimson, they shall be as wool," the passage Beyond the Chariots uses at key points in the plot.
Chuck told of a 22 year-old man who was supporting his new bride and his elderly father. He became a Christian. Muslims in his town (in an unnamed Islamic nation) carried him to their school and told him to renounce Isa (Jesus) or they would cut off one of his fingers. He wouldn't, so one at a time, with the choice to renounce given each time, they cut off each of his fingers and both of his hands. They tied him to a tree and left him there overnight. By morning he had bled to death. The father and widow struggled to support themselves until two men approached them and said they had killed the man. They had become believers in Isa and pledged to care for them in his Name.