“The thought appears to be that it is love that carries into effect the law of God; love constitutes the fulfillment of the law. It is the motive and active principle of fulfillment. . . . If we may use the metaphor, love fills to the brim the cup which the law puts into our hands. Love is the first drop; it is the last drop; and it is all the drops in between” (John Murray, Principles of Conduct, pp. 22–23).
In preparing for the next 101 Bible Study I ran across this:
For Paul, faith and works, that is, an extraspective trust in and reliance on Christ, as an act of obedience, and other acts of obedience are distinct from each other but inseparable. In fact, we may say, faith and good works, thus distinguished, are always synecdochic. To speak of the one invariably has the other in view; they are unintelligible apart from each other. They always exist without confusion, yet inseparably. James 2:18, “Show me your faith without your works and I will show you my faith by my works”–which admits of no exceptions for those in restored fellowship, by faith, with God–is a fair commentary on Paul in this regard.
From this perspective, it should be appreciated that the antithesis between law and gospel is not an end in itself, it is not a theological ultimate. That antithesis arises not by virtue of creation, but as the consequence of sin, and the gospel functions to overcome it. The gospel removes 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 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.
(Richard B. Gaffin, Jr., By Faith, Not by Sight: Paul and the Order of Salvation, pp. 117-118)
There’s a lot to chew on in these few sentences! In context Gaffin is discussing the concept of faith working through love in Galatians 5:6 and similar expressions in Ephesians 2:10, 1 Thessalonians 1:3 and 2 Thessalonians 1:11.