Commenting on the fact that the Corinthians had teachers denying the Resurrection, Luther says:

We are to think of this as put before our eyes as a terrible example which serves to startle and to warn us; and if such spirits were to arise in our midst, we must not permit this article to be taken from us or to be perverted. For I regret to say that I am worried that our great ingratitude merits that some men will arise also among us and publicly deny this article. Therefore it is indeed necessary that we pray earnestly, sincerely, and incessantly to have the pulpit remain pure, so that such affliction may be prevented or checked. For the pulpit can still staunchly resist all sorts of error and endure the whole world’s malice. Let whoever will be converted, be converted; and whoever does not wish to be, let him be gone. At least some will be saved. But where darkness encompasses the whole world and Christians are few in number and, moreover, when the pulpits are occupied by worthless, pernicious pastors, the time will not be far distant when thunder, lightning, and every plague of false doctrine will burst in upon us unexpectedly and before we are aware of it, which believes neither this nor any other article of faith. And we will have to tolerate pastors who mislead us with such loose prattle of reason, yes, even of the vulgar, beastly understanding which sows also have, such as those people in Corinth also shared, as we shall see. Therefore Paul takes this matter very seriously in order to preserve his people in the faith in this article against such abominable factions. And he substantiates this article so mightily that even the gates of hell cannot undo matters wherever the Word is adhered to and one does not give way to let blind, foolish reason indulge in subtle arguments; for reason knows nothing and can comprehend nothing of such sublime matters.

Martin Luther, Luther’s Works, Vol. 28: 1 Corinthians 7, 1 Corinthians 15, Lectures on 1 Timothy, ed. Jaroslav Jan Pelikan, Hilton C. Oswald and Helmut T. Lehmann, 1 Co 7:40 (Saint Louis: Concordia Publishing House, 1999).