Luther's response:“The law terrifies those it is not supposed to. Therefore the law is not to be taught, since, when the law is taught, then those are saddened and feel the power of the law who ought to rejoice instead. Contrariwise, those hardened, to whom the law pertains, do not care.”
The law is already mitigated greatly by the justification which we have because of Christ; and it thus ought not to terrify the justified. Yet meanwhile Satan himself comes along and makes it often overly harsh among the justified. This is why it happens that those are often terrified who ought not to be, by the fault of the devil.
Yet the law is nonetheless not to be removed from the temples; and it is indeed to be taught, since even the saints have sin left in their flesh which is to be purged by the law, until it is utterly driven out. For this wrestling match remains for the saints as long as they live here. Here they fight by day and night. There they finally overcome through Christ.
Before justification the law ruled and terrified all whom it touched. But the law is not to be taught in such a way among the pious, so as to accuse and condemn, but so as to admonish to good. For I ought not to say or preach: You are not under the remission of sins. Likewise: You will be condemned; God hates you etc. For these sayings do not pertain to those who have received Christ, but address the ruthless and wild. The law then is to be attenuated for them and is to be taught them by way of exhortation: Once you were gentiles; now, however, you are sprinkled and washed by the blood of Christ (cf. Eph. 2:11, 13; 1 Cor. 6:11). Therefore now offer your bodies to obey righteousness, putting away the desires of the flesh, lest you become like this world (cf. Rom. 12:1-2; 6:13; Eph. 4:22). Be imitators of the righteousness of good works (cf. Tit. 2:14) and do not be unrighteous, condemned like Cain etc.; you have Christ. (211–213)This is how we are to preach the law according to Luther: " . . . so as to admonish to good. . . . by way of exhortation . . . ." The law is not just for the lawless, to terrify. It is to be preached to the pious so as to admonish to good.