Recent thinking about the connection between MMA and Christianity (useful articles here and here) led back further to Muscular Christianity, the late 19th and early 20th Century movement that held that a strong, physically active body and vigorous masculinity leads to a healthy Christian life (the idea is hardly dead, as witnessed every time an NFL player prays after scoring a touchdown).
The most influential advocate of Muscular Christianity was Billy Sunday, a baseball star in the 1880s who converted to evangelical Christianity and quit the sport in 1891 to spread the good news. His popularity grew as he barnstormed the country, and in his heyday in the 1910s and early 1920s, Sunday could draw tens of thousands of people to his sermons. He counseled Theodore Roosevelt and Woodrow Wilson, grew rich, and played a major part in pushing through Prohibition in 1919.
Sunday’s popularity declined with the spread of radio and movies, and he died in 1935. I’d read about him but had never seen him actually preach. Found this video pretty mesmerizing: