MAN AS A SINNER
MAN DOES not, by himself, understand his own sinfulness, at least not in its real nature and depth. Admittedly he has by nature a partial knowledge of sin. God's law is written by nature in his heart. Insofar as he accepts it, he also knows from it that he transgresses it and sins.1 But just as without the word and the enlightenment of the Holy Spirit he cannot know the full extent of the demand God makes, so the sin in the depths of his heart and his inner impurity also remain hidden. “Man's heart is so deep that we cannot investigate it for ourselves.” The psalmist [Ps. 139:23] therefore asks the Lord to let him know his sin.2 Sin is infinitely great, especially sin against the First Commandment “What an abyss unfaith is!” How is it possible that a man could plumb its depths and express it by himself.3 By nature he perhaps recognizes certain individual sins but not the “basic, main, and really mortal sin,” the primal or original sin which is essentially unfaith toward God and his Christ, the sin against the First Commandment. Man also does not know where this sin comes from. He can know of all those things only after God's word has told him of them. The Scripture bears witness to him that he not only sins here and there but that there is little good in his nature and that whatever good there is is misused.5 Man becomes com
1WA 3911, 367.
2WA 3911, 323.
3WA 3911, 366. “Then you shall know that you cannot make this sin great
enough, for absolutely no man can ever discover or comprehend his wickedness.
since it is infinite and eternal.” WA 8, 113; LW 32, 240.
4 “Radical sin, deadly and truly mortal, is unknown to men in the whole
wide world.… Not one of all men could think that it was a sin of the world
not to believe in Christ Jesus the Crucified.” WA 391, 84; LW 34, 154. “A
man by his own nature does not know where sin comes from nor does he even
know sin itself. A knowledge of sin, however, remains in man through the
word of God.” WA 3911, 365. Cf. ibid., p. 366 and WA 8, 104
5WA 391, 86; LW 34. 156.