Still, however, even the good are sometimes affected by this inconsiderate zeal for righteousness, though we shall find that this excessive moroseness is more the result of pride and a false idea of sanctity, than genuine sanctity itself, and true zeal for it. Accordingly, those who are the most forward, and, as it were, leaders in producing revolt from the Church, have, for the most part, no other motive than to display their own superiority by despising all other men.
Well and wisely, therefore, does Augustine say, “Seeing that pious reason and the mode of ecclesiastical discipline ought specially to regard the unity of the Spirit in the bond of peace, which the Apostle enjoins us to keep, by bearing with one another (for if we keep it not, the application of medicine is not only superfluous, but pernicious, and therefore proves to be no medicine); those bad sons who, not from hatred of other men’s iniquities, but zeal for their own contentions, attempt altogether to draw away, or at least to divide, weak brethren ensnared by the glare of their name, while swollen with pride, stuffed with petulance, insidiously calumnious, and turbulently seditious, use the cloak of a rigorous severity, that they may not seem devoid of the light of truth, and pervert to sacrilegious schism, and purposes of excision, those things which are enjoined in the Holy Scriptures (due regard being had to sincere love, and the unity of peace), to correct a brother’s faults by the appliance of a moderate cure” (August. Cont. Parmen. cap. 1). To the pious and placid his advice is, mercifully to correct what they can, and to bear patiently with what they cannot correct, in love lamenting and mourning until God either reform or correct, or at the harvest root up the tares, and scatter the chaff (Ibid. cap. 2).
Let all the godly study to provide themselves with these weapons, lest, while they deem themselves strenuous and ardent defenders of righteousness, they revolt from the kingdom of heaven, which is the only kingdom of righteousness. For as God has been pleased that the communion of his Church shall be maintained in this external society, any one who, from hatred of the ungodly, violates the bond of this society, enters on a downward course, in which he incurs great danger of cutting himself off from the communion of saints.
Let them reflect, that in a numerous body there are several who may escape their notice, and yet are truly righteous and innocent in the eyes of the Lord. Let them reflect, that of those who seem diseased, there are many who are far from taking pleasure or flattering themselves in their faults, and who, ever and anon aroused by a serious fear of the Lord, aspire to greater integrity.
Let them reflect, that they have no right to pass judgment on a man for one act, since the holiest sometimes make the most grievous fall.
Let them reflect, that in the ministry of the word and participation of the sacraments, the power to collect the Church is too great to be deprived of all its efficacy, by the fault of some ungodly men.
Lastly, let them reflect, that in estimating the Church, divine is of more force than human judgment.
John Calvin, Institutes of the Christian Religion, Book IV, chapter I, 16.