Calvin on public confrontation of false religion

Great words here from Calvin (commenting on John the Baptist's preaching) on how faithful gospel ministers should confront false religion:

As to the loud and open rebuke, which was administered to them in presence of all, it was for
the sake of others; and that is the reason why Luke mentions, that it was addressed to multitudes,
(Luke 3:7.) Though the persons whom John reproved were few in number, his design was to strike
terror on all; as Paul enjoins us to regard it as the advantage of public rebukes, “that others also
may fear,” (1 Timothy 5:20.) He addresses directly the Pharisees and Sadducees, and at the same
time, addresses, through them, a warning to all, not to hold out a hypocritical appearance of
repentance, instead of a true affection of the heart. Besides, it was of great importance to the whole
nation to know what sort of people the Pharisees and Sadducees were, who had miserably corrupted
the worship of God, wasted the church, and overturned the whole of religion; — in a word, who
had extinguished the light of God by their corruptions, and infected every thing by their crimes.

It is probable, therefore, that John publicly attacked the Pharisees, for the benefit of the whole
church of God, that they might no longer dazzle the eyes of simple men by empty show, or hold
the body of the people under oppression by wicked tyranny. In this respect, it was a remarkable
display of his firmness, that those, who were highly esteemed by others, were not spared on account
of their reputation, but sternly reduced, as they deserved, to their proper rank. And thus ought all
godly instructors to be zealous, not to dread any power of man, but boldly strive to “cast down
every high thing that exalteth itself” against Christ, (2 Corinthians 10:5.)

If John, the organ of the Holy Spirit, employed such severity of language in his opening address
to those who voluntarily came to be baptized, and to make a public profession of the gospel; how
ought we now to act towards the avowed enemies of Christ, who not only reject obstinately all that
belongs to sound doctrine, but whose efforts to extinguish the name of Christ are violently maintained
by fire and sword? Most certainly, if you compare the Pope, and his abominable clergy, with the
Pharisees and Sadducees, the mildest possible way of dealing with them will be, to throw them all
into one bundle. Those, whose ears are so delicate, that they cannot endure to have any bitter thing
said against the Pope, must argue, not with us, but with the Spirit of God. Yet let godly teachers
beware, lest, while they are influenced by holy zeal against the tyrants of the Church, they mingle
with it the affections of the flesh. And as no vehemence, which is not regulated by the wisdom of
the Spirit, can obtain the divine approbation, let them not only restrain their feelings, but surrender
themselves to the Holy Spirit, and implore his guidance, that nothing may escape them through
inadvertency.