The temporary nature of the law-gospel antithesis

"the antithesis between law and gospel is not an end in itself. It is not a theological ultimate. Rather, that antithesis enters not by virtue of creation but as the consequence of sin, and the gospel functions for its overcoming. The gospel is to the end of removing an absolute law-gospel antithesis in the life of the believer. How so? Briefly, apart from the gospel and outside of Christ the law is my enemy and condemns me. Why? Because God is my enemy and condemns me. But with the gospel and in Christ, united to him by faith, the law is no longer my enemy but my friend. Why? Because now God is no longer my enemy but my friend, and the law, his will, the law in its moral core, as reflective of his character and of concerns eternally inherent in his own person and so of what pleases him, is now my friendly guide for life in fellowship with God"

(italics original, p. 103, Richard Gaffin, By Faith, Not by Sight: Paul and the Order of Salvation)

I like that, although I don't fully agree. I think that he is right that the purpose of the second use of the law is to drive us to the gospel, which enables us to return to the law and use it in its third use. But for the Christian who is both the old man and the new man, we need to use it both as enemy and friend.

Compare Timothy Wengert commenting on Article six of the Formula of Concord:

faith in Christ truly makes all things new, even our relation to the law and works. To be sure, there are "works of the law" (par. 5). There are threats and coercion: "Do this or else!" The unbeliever and our own flesh must be forced [...]

But think how our of place this coercion sounds in the language of love (par. 6). If the beloved says, "Kiss me!" what kind of answer is "Do I have to?"

[...] To be sure the law remains the law (par. 7). The Ten Commandments contain enough for us to do to last a lifetime. However, when the law hits the old creature - whether in the unrepentant or in the flesh of the believer - it can only threaten and coerce. But when the believer, as God's new creature of faith, hears the law, all threats drop away, and there remains a willingness that comes not from ourselves (we cannot make ourselves willing), but from God. Then we hear only the voice of the beloved, and there is no coercion, only faith and love.

(p.99, A Formula for Parish Practice)