We, however, hear what the Holy Spirit teaches about those who are defiled: there is nothing pure or clean in anything they do. Just suppose that all this tomfoolery or, rather, all these abominations of the papists, were not evil by nature. It is, nevertheless, the case that, according to Paul’s teaching, they would be defiled, since the papists would still be stained by sin. Imagine one of them entering a church. He would need thirty or so lakes – or rather seas! – in order to wash himself clean. Yet all he takes is three drops of holy water, and he believes that he is completely cleansed in God’s sight. Then, too, he would require a vast array of lights to see by. All the light in the world is useless to him, for he is a blind wretch who knows nothing, a man made brutish by his ignorance. Yet he is content with a few bright glimmers of light and discerns nothing in God’s truth. They tirelessly trot about hearing Mass, but what do they gain by all that nonsense? They have, it is true, gone to endless pains, and they think God should be well pleased by the efforts they have made to serve Him in this way. But, whatever they do, they show no signs of change: they still wallow in their filth and unbelief, and they do not turn back to God.
From: Sermons on Titus by John Calvin; translated from the French by Robert White (Edinburgh: The Banner of Truth Trust, 2015), pp. 145-146. From “The Tyranny of Tradition,” a sermon on Titus 1.15-16.