One of the reasons for which Martin Luther was excommunicated was his contention that “the burning of heretics is against the will of the Holy Spirit.“
In a time when the church freely used coercion and punishment to enforce its teachings, Luther insisted that faith can never be a matter of compulsion. To be sure, the state may use coercion and punishment to maintain external order–for example, to put down the anarchy of the peasant revolt–but he opposed the use of force in matters of an individual’s inner conscience or religious convictions.
In my research into my previous post The Futility of Coercing or Punishing Belief, on the way “cancel culture” is bringing back the notion that people should be forced to agree with certain ideas and be punished if they don’t, I kept coming across the name of Martin Luther. He is regularly cited for his teaching, which was much against the grain of his time, that matters of belief, religious faith, or convictions of conscience cannot be imposed on anyone and that governments should not try to regulate what their subjects think in their hearts. (See, for example, Martin Luther and the Long March to Freedom of Conscience and Luther’s Challenge to the Conscience of the West.)
Luther makes this point a number of times, but here is what he says in his important 1523 treatise Temporal Authority: To What Extent It Should Be Obeyed, in which he shows that coercion in matters of inner convictions is wrong, impossible, and counter-productive:
How he believes or disbelieves is a matter for the conscience of each individual, and since this takes nothing away from the temporal authority the latter should be content to attend to its own affairs and let men believe this or that as they are able and willing, and constrain no one by force. For faith is a free act, to which no one can be forced. Indeed, it is a work of God in the spirit, not something which outward authority should compel or create. Hence arises the common saying, found also in Augustine, “No one can or ought to be forced to believe.”Moreover, the blind, wretched fellows fail to see how utterly hopeless and impossible a thing they are attempting. For no matter how harshly they lay down the law, or how violently they rage, they can do no more than force an outward compliance of the mouth and the hand; the heart they cannot compel, though they work themselves to a frazzle. . . .Why do they persist in trying to force people to believe from the heart when they see that it is impossible? In so doing they only compel weak consciences to lie, to disavow, and to utter what is not in their hearts. They thereby load themselves down with dreadful alien sins, for all the lies and false confessions which such weak consciences utter fall back upon him who compels them. Even if their subjects were in error, it would be much easier simply to let them err than to compel them to lie and to utter what is not in their hearts. . . .Moreover, faith and heresy are never so strong as when men oppose them by sheer force, without God’s word. For men count it certain that such force is for a wrong cause and is directed against the right, since it proceeds without God’s word and knows not how to further its cause except by naked force, as brute beasts do.
Since faith is a gift of the Holy Spirit, no one can be forced to believe. It follows that heresies, doctrinal errors, and mistaken faiths must be dealt with by the Word, not the Sword.
This is not to say that Luther advocated religious freedom in the way we know it now. Though rulers should not presume to punish inner beliefs, they may punish external behavior. That includes external behavior that is religiously motivated, such as public teaching on the part of heretics and open statements of “blasphemy.”
Luther was fine with the persecution of Anabaptists, not for their religious convictions, but for being “seditious,” as when they reject military service, private property, and temporal laws. (See Catholic apologist Dave Armstrong who excoriates Luther for this, quoting his Commentary on the 82nd Psalm, which, however, makes these distinctions.) And Luther, infamously, would in 1543 call for the persecution of Jews, seemingly not just for their actions but for their faith, contradicting his own principle.
Though Luther was oblivious to many of the liberties we have today, many of those who did formulate those liberties–from John Locke to James Madison–built on his foundation and gave Luther credit.