Nor was Luther's sharp pen long idle against Rome, as indeed might have been anticipated from his letter to Kronberg. He found his chief occasion for attack in a series of new edicts and other measures of the German bishops against the innovations—the abolition of clerical celibacy, the transgression of the laws of fasting, and so on. For this purpose ecclesiastical visitations were undertaken by the Bishops of Meissen and Merseburg, such as have already been alluded to when Luther went to Zwickau.
Luther's sermons against the abuse of Christian liberty were followed by a small tract entitled 'On the necessity of avoiding human doctrine.' He did not mean it, as he said, for those 'bold, intemperate heads;' but he wished to preach Christian liberty to the poor, humble consciences, enslaved by monkish vows and ordinances, that they might be instructed how, by God's help and without danger, to escape and to use their liberty discreetly. Against the existing Romish episcopacy he declared war to the knife in a treatise 'Against the Order, falsely called Spiritual, of Pope and Bishops.' He who had been robbed of his title of priest and doctor by the displeasure of Pope and Emperor, and from whom, by Papal bulls, the 'mark of the beast' (Rev. xiii. 16) was washed off, confronts the 'popish bishops' now, as 'by God's grace, preacher at Wittenberg.'
Luther's further writings against the Romish Churchdom and dogma do not possess the same interest for us as his earlier ones, inasmuch as they no longer show the progress and development of his own views on the Church. In the violent language he now employs he vents his chief anger in complaining that he, and the truth he represented, 'had been condemned unheard—an unexampled proceeding—unrefuted, and in headlong and criminal haste.'
With reference to the attack he had made on the 'episcopal masqueraders' in the tract above mentioned, Luther remarked in a letter to Spalatin on July 26 that he had purposely been so sharp in it, because he saw how vainly he had humbled himself, yielded, prayed and complained. And he added that he would just as little flatter, the King of England.
King Henry VIII., who later on, for other reasons, broke so entirely with the Church of Rome and began reforms after his own fashion, had at that time gained for himself from the Pope the title of 'Defender of the Faith,' on account of a learned scholastic treatise against Luther's 'Babylonish Captivity.' This treatise had made such a stir, that Luther thought it expedient to answer it in one of his own. The latter, originally written in Latin, gives a carefully considered explanation of the points of doctrine at issue, and proceeds to prove the propositions he had previously advanced. He points out fundamental, and, indeed, irreconcilable variance between his principles and those of the King, by showing how he, Luther, fought for freedom and established it, while the King, on the contrary, took up the cudgels for captivity, without even attempting to justify it by argument, but simply kept talking of what it consists of, and how people must be content to remain in it. In fact, the whole book was a mere reiteration of the dogmas of ecclesiastical authorities, of the Councils, and of tradition, always taking it for granted that these dare not be disputed. 'I do not need,' says Luther,' the King to teach me this.' But the personal tone adopted by Luther against Henry went beyond anything that his expressions to Spalatin might have led one to expect, and was even more marked in a German edition of his treatise, which he published after the royal one had been translated into German. The King had, moreover, set the example of abuse, as coarse and defiant as that of his opponent. Luther did not shrink from an incidental remark at the expense of other princes. 'King Henry,' he says, 'must help to prove the truth of the proverb, that there are no greater fools than kings and princes.'
But the most important among the works which Luther was now led to undertake by his opposition to the Romish Church and her teaching, and by her hostile proceedings against himself, was a treatise on the secular power, which he began in December, as soon as he had finished the translation of the five Books of Moses. It appeared under the title of 'On the Secular Power, and how far obedience is due to it.'
How far obedience is due to it? This was the question provoked by the commands and threats of punishment with which Catholic princes were now endeavouring to aid the spiritual power in suppressing the gospel, the writings on reform, and especially the new translation of the Bible. The question was, how far a Christian was bound to obey.
Nor had Luther to step forward less decisively as the champion of the rights, the Divine authority, and the dignity of the civil power, against the pretensions of the Catholic Church. Words of Jesus such as these lay before him: 'But I say unto you, that ye resist not evil: but whosoever shall smite thee on thy right cheek, turn to him the other also.' How could these words be reconciled with the fact that the secular arm resisted wrong with force, and raised the sword against the evil-doer? The Church of the middle ages and the School theology maintained that these words were not general moral commands for all Christians, but merely advice for those among them who wished to attain a higher degree of perfection. Hereby the whole civil government with its authorities was assigned a lower grade of ordinary morality, whilst higher morality or true perfection was to be represented in the priestly office and monasticism. On the other hand, friends of Luther, ere now, while taking note that Christ had spoken these words direct to all his disciples, and therefore to all Christians, had been troubled to know how to establish, with regard to Christians, the rights and duties of temporal power.
With respect to this second point in particular Luther now gives his explanation. Those words of Christ were unquestionably commands for all Christians. They demand of every Christian that he should never on his own account grasp the sword and employ force; and if only the world were full of good Christians there would be no need of the, sword of secular authority. But it is necessary to wield it against evil for the general welfare, to punish sin and to preserve the peace; and therefore the true Christian, in order thereby to serve his neighbour, must willingly submit to the rule of this sword, and, if God assigns him an office, must wield this sword himself. This command of Scripture is confirmed by other passages, as for instance by the words of the Apostle: 'Let every soul be subject unto the higher powers. For there is no power but of God: the powers that be are ordained of God. For he is the minister of God to thee for good … for he beareth not the sword in vain.' (Romans xiii.). Luther thus ranks the vocation of civil government together with the other vocations of moral life in the world. They are all, he said, instituted by God, and all of them, no less than the so-called priestly office, are intended and able to serve God and one's neighbour. These were ideas which laid the foundation for a new Christian estimate of political, civic, and temporal life in general. Thus, later on, the Augsburg Confession rejected the doctrine that to attain evangelical perfection, a man must renounce his worldly calling, as also the theory of the Anabaptists, who would allow no Christian to hold civil office or to wield the sword.
But Luther, while thus determining the province of secular authority, took care to impose limits on its jurisdiction, and to guard against those limits being invaded. The true spiritual government, as instituted by Christ, was intended to make men good, by working upon the soul by the Word, in the power of the Spirit. The temporal government, whose duty it was to secure external peace and order, and to protect men against evil-doers, extends only to what is external upon earth,'—over person and property. 'For God cannot and will not allow anyone but Himself alone to rule the soul.'—'No one can or shall force another to believe.'—'True is the proverb: "Thoughts are free of taxes."' We must 'obey God rather than man,' as St. Peter says: these words impose a limit on temporal power. Luther is aware of the objection, that the temporal power does not force a man to believe, but only outwardly guards against heretics, to prevent them from leading the people astray with false doctrines. But he answers: 'Such an office belongs to bishops, and not to princes. God's Word must here contend for mastery. Heresy is something spiritual, that cannot be hewn with steel nor burned with fire.' And among these invasions of the province and office of the Word, Luther includes the edict to confiscate books. Herein must subjects obey God rather than such tyrannical princes. They are to leave the exercise of outward power, even in this matter, to the civil authorities, they must never venture to oppose them by force; they must suffer it, if men invade their houses, and take away their books or property. But if they attempt to rob them of their Bible, they must not surrender a page or a letter.