More from Dr. Luther's 1535 Lectures on Galatians:
"‘I wish those who unsettle you would mutilate themselves!’ (Galatians 5:12). Is this proper for an Apostle, not only to declare that the false apostles are troublemakers, to condemn them, and to hand them over to the devil but even to call evil down upon them and to wish that they would perish and be utterly destroyed — in other words, to curse them? It seems to me that Paul is making an allusion to circumcision, as though he were saying: ‘They are forcing you to be circumcised. I wish that they themselves would be mutilated from the very foundation and root!’
"Here the question arises whether Christians are permitted to curse. Yes, they are permitted to do so, but not always and not for just any reason. But when things come to the point where the Word is about to be cursed or its teaching — and, as a consequence, God Himself — blasphemed, then you must invert your sentence and say: ‘Blessed be the Word and God! And cursed be anything apart from the Word and from God, whether it be an apostle or an angel from heaven!’ Thus Paul says earlier: ‘Even if we, or an angel from heaven, etc., let him be accursed’ (Gal. 1:8). Here one can tell that ‘a little yeast’ was so important to Paul that he even presumed to curse the false apostles, men who gave the appearance of great authority. Therefore let us not underestimate the importance of the yeast of doctrine either. No matter how little it is, if it is despised, this causes the eventual loss of truth and salvation, and the denial of God. For when the Word is distorted and, as necessarily follows, when God is denied and blasphemed, there is no hope of salvation left. But if we are the ones who are slandered, cursed, and killed, there is still One who can revive us and set us free from the curse, from death, and from hell.
"Therefore let us learn to praise and magnify the majesty and authority of the Word. For it is no trifle, as the fanatics of our day suppose; but one dot (Matt. 5:18) is greater than heaven and earth. Therefore we have no reason here to exercise love or Christian concord, but we simply employ the tribunal; that is, we condemn and curse all those who insult or injure the majesty of the divine Word in the slightest, because ‘a little yeast leavens the whole lump’ (Gal. 5:9). But if they let us have the Word sound and unimpaired, we are prepared not only to exercise charity and concord toward them but to offer ourselves as their slaves and to do anything for them. But if they refuse, let them perish and be banished to hell, and not only they themselves but the whole world with all its godly and ungodly inhabitants, just as long as God remains; for if He remains, life and salvation remain, and so do the truly godly.
"Therefore Paul acts properly when he curses these troublemakers and pronounces the sentence that they are accursed along with everything they are or teach or do, and when he calls down upon them the evil that they may be cut off from this life, and especially from the church, that is, that God may not govern and prosper their teaching and all their actions. This curse proceeds from the Holy Spirit. Thus in Acts 8:20 Peter curses Simon: ‘Your silver perish with you!’ The use of curses is frequent in Holy Scripture against those who disturb the Spirit this way, especially in the Psalms. Thus: ‘Let death come upon them; let them go down to hell alive’ (Ps. 55:15). And again: ‘The wicked shall depart to hell’ (Ps. 9:17).
"Up to this point Paul has been reinforcing the doctrine of justification with powerful argument. Now, in order not to skip anything, he has interspersed the discussion with rebukes, commendations, exhortations, and warnings. At the end he has added the example of himself, his own suffering of persecution on account of this doctrine. In this way he warned the faithful not to be offended or frightened but to rejoice and be glad if they see tumults, stumbling blocks, and sects arise during the age of the Gospel. For the more violently the world rages against the Gospel, the better the position of the Gospel is.
"This should be a very pleasant comfort for us. For it is sure that the world hates and persecutes us for no other reason than that we present the truth of the Gospel. It does not accuse us of being thieves, adulterers, murderers, etc.; but what it despises in us is solely this, that we teach Christ faithfully and purely, and that we do not forsake the heritage of the truth. Therefore we should know for certain that our doctrine is holy and divine, because the world hates it so bitterly. Otherwise there is no doctrine too wicked, stupid, ridiculous, or dangerous for the world to accept it, embrace and defend it gladly, in fact, to treat it reverently, support it, fawn upon it, and convert everyone to it. The teaching of godliness, life, and salvation, together with its ministers, is the only one that it despises and treats in an utterly shameful way. This is evident proof that the world is angry with us only because of its hatred of the Word. Therefore when our opponents raise the objection against us that our doctrine produces nothing but war, sedition, stumbling blocks, sects, and endless other evils, let us reply: ‘Blessed be the day when it becomes possible to see all this! But the whole world is in an uproar. All right. If it were not in an uproar, and if the devil were not in such a rage and were not creating such havoc everywhere, we would not have the pure doctrine which such tumults and havoc inevitably follow. Therefore what you think of as evil we regard as the highest good.’"
(Luther’s Works, Volume 27, CPH 1963)