This Commandment seems small, and yet is so great, that he who would rightly keep it must risk and imperil life and limb, goods and honor, friends and all that he has; and yet it includes no more than the work of that small member, the tongue, and is called in German Wahrheit sagen, "telling the truth" and, where there is need, gainsaying lies; so that it forbids many evil works of the tongue. First: those which are committed by speaking, and those which are committed by keeping silent. By speaking, when a man has an unjust law-suit, and wants to prove and maintain his case by a false argument, catch his neighbor with subtilty, produce everything that strengthens and furthers his own cause, and withhold and discount everything that furthers his neighbor's good cause; in doing which he does not do to his neighbor as he would have his neighbor do to him. This some men do for the sake of gain, some to avoid loss or shame, thereby seeking their own advantage more than God's Commandment, and excuse themselves by saying: Vigilanti jura subveniunt, "the law helps him who watches"; just as if it were not as much their duty to watch for their neighbor's cause as for their own. Thus they intentionally allow their neighbor's cause to be lost, although they know that it is just. This evil is at present so common that I fear no court is held and no suit tried but that one side sins against this Commandment. And even when they cannot accomplish it, they yet have the unrighteous spirit and will, so that they would wish the neighbor's just cause to be lost and their unjust cause to prosper. This sin is most frequent when the opponent is a prominent man or an enemy. For a man wants to revenge himself on his enemy: but the ill will of a man of prominence he does not wish to bring upon himself; and then begins the flattering and fawning, or, on the other hand, the withholding of the truth.
Here no one is willing to run the risk of disfavor and displeasure, loss and danger for the truth's sake; and so God's Commandment must perish. And this is almost universally the way of the world. He who would keep this Commandment, would have both hands full doing only those good works which concern the tongue.
And then, how many are there who allow themselves to be silenced and swerved aside from the truth by presents and gifts! so that in all places it is truly a high, great, rare work, not to be a false witness against one's neighbor.
II. There is a second bearing of witness to the truth, which is still greater, with which we must fight against the evil spirits;and this concerns not temporal matters, but the Gospel and the truth of faith, which the evil spirit has at no time been able to endure, and always so manages that the great among men, whom it is hard to resist, must oppose and persecute it. Of which it is written in Psalm lxxxii, "Rid the poor out of the hand of the wicked, and help the forsaken to maintain his just cause."Such persecution, it is true, has now become infrequent; but that is the fault of the spiritual prelates, who do not stir up the Gospel, but let it perish, and so have abandoned the very thing because of which such witnessing and persecution should arise;and in its place they teach us their own law and what pleases them. For this reason the devil also does not stir, since by vanquishing the Gospel he has also vanquished faith in Christ, and everything goes as he wishes. But if the Gospel should be stirred up and be heard again, without doubt the whole world would be aroused and moved, and the greater portion of the kings, princes, bishops, doctors and clergy, and all that is great, would oppose it and rage against it, as has always happened when the Word of God has come to light; for the world cannot endure what comes from God. This is proved in Christ, Who was and is the very greatest and most precious and best of all that God has; yet the world not only did not receive Him, but persecuted Him more cruelly than all others who had ever come forth from God.