Deuteronomy 13:1

After having restrained the Israelites from the strange delusions of the Gentiles, Moses now forbids them from being too credulous if false teachers should arise from among themselves, and warns them diligently to beware of all novel inventions, and not to turn aside in the very least degree from the Law, at the instigation of any one. For there is peril to be apprehended, not only from professed and manifest enemies, or from foreign superstitions, but Satan plots also by means of intestine deceits, and abuses the holy name of God in order to betray us. Therefore it behoves that the faith of the godly should not only be externally fortified and protected by the ramparts of the word, lest corruption should creep in from without, but also that it should be garrisoned within by the same word, lest novel imaginations should secretly insinuate themselves and destroy the purity of doctrine. Moreover, we gather from this prohibition that there is such certainty in the divine doctrines as to prevent our faith from being undermined or shaken, provided it has put forth into them living roots, and is firmly grounded upon them. For it would be vain for God to warn us against giving admission to false teachers, unless He, at the same time, shewed the means by which they were to be guarded against. And assuredly nothing can be more improbable than that religion should be ambiguous; and since the rule and definition of it is faithfully prescribed and set forth in the Law, justly does God require of His people that they should not waver, but constantly persist in the truth delivered to them. For truly does Isaiah declare respecting the Law, that in it it has not been said in vain to the seed of Jacob, that they should seek God’s face. (297) (Isaiah 45:19.) But, in seeking God, it would not be sufficient to teach what is right, unless men’s minds are established in it; it is requisite, therefore, that religion should be sure and firm, or it will not be duly ordered. Nor is there any doubt that what Paul witnesses of the Gospel was true also of the Law, viz., that it armed its disciples against all the storms of temptation, that they “should be no more children, tossed to and fro, and carried about with every wind of doctrine, by the sleight of men,” etc. (Ephesians 4:14.) But the words before us, when examined more closely and regularly, will shew, with greater clearness, the aim of the matter.

1.If there arise among you. We already perceive that the question is not respecting the falsities and errors which Satan had spread throughout the world, but respecting those which were to appear in the very bosom of the Church, as if it had been said that the Law was not only given in order to separate the Israelites from heathen nations, but to keep themselves in the purity and integrity of the faith; for just as now-a-days Christ betroths the Church to Himself by the preachers of the Gospel, (2 Corinthians 11:2,) that she may devote herself as a chaste virgin to His obedience, and not allow herself to be withdrawn from the simplicity of the faith by any seductions; so of old God espoused His ancient people to Himself, and bade them close their ears against impostors, who are, as it were, the seducers of Satan tempting them to violate that sacred and special bond of marriage whereby God would be united with His people. We shall speedily see wherefore God would have His Church exposed to this evil. Meanwhile it is useful to admonish believers of their danger, that they may be constantly watching against the snares of Satan; for this abomination did not only prevail in that particular age, but it will have its evil influence even to the end of the world. We must remember what Peter says, that “as there were false prophets among” the Jews of old, so also in the kingdom of Christ

“there shall be false teachers who privily shall bring in damnable heresies.” (2 Peter 2:1.)

Moses, however, does not merely speak of domestic enemies, but, of such as shall assume the title of Prophets in order that they may deceive with greater license and impunity. From hence we infer that it is not enough to have an honorable position, or a plausible name, whether pastor, or prophet, or priest, unless it be allied to sincerity in accordance with our calling; for who are the persons whom God here commands to be avoided and held in abomination? Just those who boasted themselves to be Prophets, but who, when carefully inquired into, were obliged to drop their mask, and driven to confusion. A particular appellation is subjoined to their general one, since the same individual is spoken of as “a dreamer of dreams,” because God of old time manifested Himself to the Prophets sometimes in visions and sometimes in dreams. Either of these, then, was an honorable pretext for conciliating favor. But the temptation which follows was still more dangerous, viz., if such an one should have commended himself by a successful prediction; for who would despise a prophecy authenticated by events, especially when Isaiah declares this to be the attribute of God alone? (Isaiah 45:21.) And the difficulty here is still increased, because in chap. 18, God appears to distinguish false Prophets from true ones by this very test. (298) Thus I resolve the difficulty, God’s claiming to Himself the glory of foretelling events does not prevent Him from occasionally conferring even on the ministers of Satan the power of prophecy respecting some particular point. Balaam was worse than any hireling crier, wishing as he did to frustrate the eternal decrees of God, and yet we know that his tongue was directed by the divine inspiration of the Spirit so as to be the proclaimer of that grace which he had been hired to quench. There is, therefore, no inconsistency in this, that a man should be a perfidious impostor, and still endowed at the same time with a particular gift of prophecy, not so as always to deliver true revelations, (as, for instance, Caiaphas, who prophesied correctly once, was not always veracious,) but in so far as by God’s permission it shall be given him to foreknow this or that, so that one example of truth-telling may be the cloak for many falsehoods. Fitly, then, and properly, in the other passage, does God, by Moses, reprove the vanity of those rash spirits who promise what is not fulfilled. For we must take into consideration His intention. Many are there who bring themselves into notice by clandestine acts, and at length boldly burst forth and boast themselves to be prophets, whilst the people are in doubt whether they ought so to consider them. But since it most frequently happens that the folly of such men is betrayed by marks of infamy and disgrace inflicted upon them from above, so that the world may see that they have spoken falsely, justly does God declare that the event of their predictions is to be regarded, lest the Israelites should promiscuously and unreflectingly receive whatever they may hear. The principle, therefore, is established, that those speak in God’s name who predict what really comes to pass; for they could not declare the truth respecting things unknown to man unless God Himself should dictate it to them. This is the tendency of the answer of Jeremiah to Hananiah, —

“The prophets that have been before me and before thee of old, prophesied both against many countries, and against great kingdoms, of war, and of evil, and of pestilence. The prophet which prophesieth of peace, when the word of the prophet shall come to pass, then shall the prophet be known, that the Lord hath truly sent him.” (Jeremiah 28:8.)

Hananiah promised that the war should end prosperously; but Jeremiah, knowing that he lied, brings him to an experimental proof of his falsehood, in case the facts should not correspond with what he had said. Thus far there is no inconsistency in our statement, that all true prophesies must proceed from God, and yet that the same Prophet who has predicted the truth may, in other points, be a deceiver And especiallylet us remark the admonition of Paul, that

“because they (the reprobate) receive not the love of the truth, that they may be saved; for this cause God sends them strong delusion, that they should believe a lie; that they all might be damned who believed not the truth, but had pleasure in unrighteousness.”
(2 Thessalonians 2:10,)

Hence we are taught that not only are the reins of Satan loosed in order that he may do injury, but that he is armed with power effectively to drag on the reprobate to final tied struction. Moses here teaches the same thing, for there are no reasonable grounds for the differences between Hebrew commentators as to the word sign. (299) It is unquestionable that signs were sometimes used in order to obtain credit for prophesies, as when Isaiah walked naked, ( Isaiah 20:2,) and Jeremiah wore a yoke on his neck, ( Jeremiah 18:10;) it is also unquestionable that Satan often deceives by magical incantations; but I have no doubt that by the words signifying the sign and the wonder, Moses here means anything incredible and unexpected, for the purpose of vaticination. The Hebrews use the word מופתים , mophethim, to express miracles whereby God portends anything future, as if He spoke from heaven. The word אות , oth, is more general, and is sometimes used for a banner, or a watchword, or signal, (symbolum.) Both are here put for extraordinary signs which testify the power of God, as if it were present; in this sense, Christ warns His disciples to beware of signs and lying prodigies. ( Matthew 24:11.) But although Satan dazzles the eyes with his illusions, so as in his false rivalry to win to himself the glory of God, yet have we shewn from St. Paul, and Moses has before declared, that impostors in their working of miracles are the ministers of God’s vengeance, in order that the reprobate may be taken in their snares. Should any object that signs would be useless, which may be as well dangerous deceptions as confirmations of the truth, I reply, that such license has never been accorded to the devil, as that the light of God should not in the end shine forth from the midst of the darkness. It will happen, therefore, that the true power of God may be obscured for a time, (as we have seen before in the history of the magicians,) but that it will never be overwhelmed. Thus in the miracles, whereby the Law was ratified, the glory of God so shone forth that they might obtain credit without any hesitation from the godly. Such, without controversy, are the miracles which authenticate the Gospel, because they present evidences inscribed upon them by God by which all suspicion of deceit is fully removed. And, indeed, since men’s minds are involved in dull stupidity, and are blind even to the ordinary course of God’s dealings, so also they are almost always mistaken with respect to miracles, unless His word enlightens them to dispel the darkness. In order, therefore, that we may duly profit by signs, an inseparable connection must be established between them and doctrine; and Moses rightly teaches that they must be repudiated who shall endeavor to pervert piety under the pretext of signs, because they impiously and wickedly divide things which God has joined together, and improperly divert to a contrary use the signs which only serve as aids to righteous doctrine. But after the religion of the Jews had been sealed by sure and evident signs, it was wrong for them to attend to accidental signs, and not altogether without base ingratitude. We now arrive at the sum of this passage, viz., that they must persevere in the worship of the one God, so that not even prodigies should have any force to shake the people’s minds. The clause, therefore, “which thou hast not known,” must be observed; whereby Moses signifies that the glory of the God which they serve was so certainly testified that their levity in turning this way or that would be inexcusable; and thus the knowledge which ought to be firmly implanted in their hearts, and to abide therein, is opposed to all the artifices of the devil, which only affect unstable minds.