The following is excerpted from Mockingbird’s Law & Gospel: A Theology for Sinners (and Saints)

If the law were simply a matter of doing or not doing, commission or omission, we might reasonably imagine we have a shot at keeping it. And sometimes the echoes of law we hear in society are strictly behavioral. Not so with the Law of God. It goes a step further. Christ himself applies the divine ordinance to motivation as well as action. In the Sermon on the Mount, instead of simply prohibiting acts of murder, he prohibits thoughts of murder. Later on he tells us not to worry about anything. It turns out he is just as concerned with the inner life as the outer.

In his summary of the Law, Jesus even commands us to… love. Taken together, these imperatives comprise a supremely laudatory code, or godly way of life. A world devoid not only of killing but anger would undoubtedly be a much better one. A world where people loved one another. So the law is not somehow problematic or bad—it is good! The problem is what it exposes in the person who hears it, namely, sin. As Gerhard Forde writes:

“The law says, ‘Thou shalt love!’ It is right; it is ‘holy, true, good.’ Yet it can’t bring about what it demands. It might impel toward the works of the law, the motions of love, but in the end they will become irksome and will all too often lead to hate. If we go up to someone on the street, grab them by the lapels and say, ‘Look here, you’re supposed to love me!’ the person may drudgingly admit that we are right, but it won’t work. The results will likely be just the opposite from what our ‘law’ demands. Law is indeed right, but it simply cannot realize what it points to. So it works wrath. It can curse, but it can’t bless. In commanding love law can only point helplessly to that which it cannot produce.”

The Law that Christ articulates does not ask that we do our best, or that we improve. It is comprehensive. Its demand reaches beyond words and deeds to thoughts and feelings. This is why theologians maintain that the Law always accuses. Lex semper accusat.

Regardless of how good we feel ourselves to be, how well we think we are doing, or how much better we think we’re becoming, there is no getting around the accusation of “Be perfect, as your heavenly Father is perfect” (Mt 5:48). To hear those words clearly is to hear that we are significantly worse off than we imagine ourselves to be—and when it gets down to motivation, even the best things we do have something in them that needs to be forgiven.

Moreover, like a husband pointing out the dishes he’s done in order to leverage some gratitude from his wife, the second we harness our good deeds for credit is the second they become less good. The motivation becomes self-seeking rather than purely altruistic.

By placing equal emphasis on action and motivation, Christ knocks the wind out of the carefully constructed images we have of ourselves. He demolishes any and all notions of self-sufficiency. We stand not only accused, but condemned (Rm 3:23).

This is not an easy message to accept.