St. John Fisher is perhaps the forgotten saint. While his times are remembered, he is not. The 20th century saw a rebirth in interest in Fisher, the only Bishops to not bend the knee to Henry VIII. His work, the Defence of the Priesthood, was written in refutation of Martin Luther's work "On the Abolition of Private Mass". It relies principally on the witness of the New Testament, then the Church Fathers to prove with certainty that the Catholic priesthood was introduced by Jesus Christ.Luther regularly responded to anyone who criticized him with abuse, but to Fisher he never made any response, not only because the treatise was unanswerable, but also because Fisher was the holiest Bishop in Christendom . This treatise, being thoroughly grounded in Holy Scripture, reveals Fisher as the true witness to the Gospel.