The Testimonies of Luther, Calvin, Knox, and Bunyan Hundreds of biographies have been written of Martin Luther, John Calvin, John Knox and John Bunyan. But there is something unique to be gained by listening to these men tell their stories in their own words. Here, in In Their Own Words, is a collection of testimonial statements drawn from the writings of Luther, Calvin, Knox, and Bunyan. We see men who candidly confessed their sins and boldly testified to the grace, mercy, and goodness of God to them. Their testimonies illustrate the great truth stated by Paul that where sin abounded, grace abounded much more, so that as sin reigned in death, even so grace might reign through righteousness to eternal life through Jesus Christ our Lord (Rom. 5:20-21).