Nothing is more common with polemic writers, than to complain of the pride of those who impugn their theories. It requires no great penetration to discern, that the pride of the writer is the source of the complaint. The charge is commonly reciprocal, and just on both sides. Would you know which is the proudest? You will not mistake the matter greatly in concluding, that it is he who on this topic makes the loudest clamour. But of all the species of pride and presumption that have ever yet appeared, it is certainly the most extravagant, for a puny mortal, the insect of a day, a reptile of the dust, to arrogate the prerogative of omniscience, to ascend the throne of the Most High, and to point the thunders of Almighty power. Is it to be wondered that such a disposition should produce a spirit of persecution? It would be miraculous if it did not. Can the man who does not hesitate to usurp one function of Omnipotence, hesitate to usurp another? Would he who scruples not to pronounce sentence, scruple to execute it if it were in his power? Yes, upon reflection I am persuaded, that far the greater part of those blind zealots themselves would stop here. We are however too amply warranted by experience to say at least, that they will not scruple to consign him to a stake in this world, whom they do not scruple, in their usurped capacity of judges, to hell-fire in the next.
We sometimes hear much of Antichrist amongst our controvertists. Who is Antichrist? It is an usurper, who, under pretence of honouring Christ, supplants him, perverting the power he has assumed to the seduction of the disciples, 2 Thess. ii. 3, &c. We have seen already, that, in the political artifices we have been combating, there is a double usurpation of the prerogatives of our Lord, both as the only infallible instructor of the people, and as the supreme judge of the world. This is therefore that malign spirit of Antichrist, whose baleful influences, have, alas! been but too widely diffused, to the unspeakable hurt of that godlike charity, without which, with all our pretensions to faith, and zeal, and knowledge, we are at best but sounding brass and tinkling cymbals, 1 Cor. xiii. 1-3.
What then shall we say of those who differ from us in important articles? What shall we say? That, in our judgment, they err, not knowing the Scriptures. What more should we say? It belongs to the Omniscient, the Searcher of hearts, and to him only, to say whether their error, if they be in an error, proceeds from pravity of disposition, or from causes in which the will had no share. Is it for us to determine, how much wood, and hay, and stubble, may be reared up on the only foundation, Jesus Christ? Though the foreign materials, by the apostle's account, will be consumed in the fiery trial they must undergo, yet the builder himself will be saved, 1 Cor. iii. 15. We are ever, like Peter, turning aside from the point in hand, (which is what immediately concerns ourselves,) and, by a curiosity much less justifiable than his, inquiring, what will become of this man? When such a question arises in thy mind, O my fellow-Christian, think thou hearest the voice of thy divine Master checking thy impertinence in the words addressed to the apostle, What is that to thee? Follow thou me? John xxi. 22.
George Campbell, "The Spirit of the Gospel a Spirit Neither of Superstition Nor of Enthusiasm," preached before the synod of Aberdeen, 9 April 1771.
I've taken this from (to give it its full name) A Dissertation on Miracles: Containing an Examination of the Principles Advanced by David Hume, Esq., in An Essay on Miracles; with a Correspondence on the Subject by Mr. Hume, Dr. Campbell, and Dr. Blair. To Which are Added, Sermons and Tracts. A New Edition. Thomas Tegg (1839) 191-192.
"Enthusiasm" in the title of the sermon doesn't mean what we would mean by it. It was common among establishment Protestants in this period to distinguish true religion from the two opposing vices of superstition (also called priestcraft) and enthusiasm. Thus, theologians of both the Church of England and the Church of Scotland saw themselves as occupying the golden mean or happy medium between Catholicism and the more radical forms of Protestantism (Baptists, Methodists, and Quakers, mostly); the former was considered excessively rigid, and the latter excessively loose, in religious and social structure (and usually doctrine as well). It was a common polemical trope, which Hume takes up for his own use in several places.