Luther emerged . . .

"When the truth was suffocated by such pervasive, thick darkness; when religion was polluted by so many godless superstitions; when the worship of God was corrupted by horrid sacrilege and His glory was lying prostrate; when the benefit of redemption was buried under many twisted opinions, people drunk on the destructive confidence of works sought salvation elsewhere than in Christ, the administration of the sacraments was partly mangled and destroyed, partly corrupted by many human inventions mixed in, partly defiled by for-profit markets; when the government of the church had degenerated into a totally confused wasteland; when those who were sitting in the place of pastors first damaged the church very much by a loose way of living; when they exercised harsh and especially harmful tyranny over souls, the people were led like a herd of cattle to destruction by every kind of error—Luther emerged, then others appeared, who with united devotion sought out reasons and ways by which religion could be freshly purged from so many corruptions, the doctrine of godliness be restored to its purity, and the church be brought together out of such distress into a tolerable condition."
—John Calvin, 'The Necessity of Reforming the Church'