John Bunyan was an English preacher, but today he's most famous for writing the seminal Pilgrim's Progress, one of history's most famous and popular allegorical works. Bunyan even has a festival in his honor within the Church of England.
Though not as well known as Pilgrim's Progress, Justification by an Imputed Righteousness is an important treatise Bunyan wrote about how Christians can save themselves:
"No Way to Heaven but by JESUS CHRIST. I. By justification with God, we stand clear, quit, free, or in a saved condition, in the approbation of His holy law. II. By justification with men, we stand clear and quit from just ground of reprehension with them. All by the imputation of the righteousness of Jesus Christ, in which we have faith working by love."