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Behold the works of the Lord, what desolations he hath made in the earth. He maketh wars to cease unto the end of the earth; he breaketh the bow, and cutteth the spear in sunder; he burneth the chariot in the fire (Psalm xlvi. 8-9).
What is said and written about war as a terrible plague is all true, but it should be remembered at the same time how much greater is the plague which war prevents.
But do you not see that the world is evil, that people do not desire to live in peace but want to rob and steal, and kill and abuse your wife and child, and take away your honour and possessions?
All over the world man fights man. No single person could save himself from this unending strife unless the little strife which is called war should check it.
Therefore God has honoured the sword so highly that He calls it His own ordinance, and does not will that we should say or think that man has invented it and ordained it. For the hand which holds this sword and kills with it is no longer a human hand, but the hand of God, so that it is not man but God that hangs, breaks human limbs on the wheel, hacks off heads, slays, and makes war. It is all His work and judgement.
Martin Luther, On whether soldiers can be saved (1526. W.A. [Weimar Edition] 19.626; repr. in Day by Day We Magnify Thee, Fortress Press, Philadelphia, 1982, p. 307).