The Law Is Holy and Good—and Impossible Apart from Christ

Now, the purpose of teaching that it is impossible to fulfill the Law is not to encourage or excuse carelessness, sloth, and intentional negligence…rather, it is so that

• (1) we, confessing the powerlessness of our abilities and the imperfection of our own righteousness, may flee for refuge to Christ, “who has redeemed us from the curse of the Law, having been made a curse for us” (Gal. 3:13); “through [Him] God has done what was impossible for the Law” (Rom. 8:3), “that He might be the end of the Law for righteousness for all who believe” (Rom. 10:4).  The glory of having perfect righteousness must be reserved for Christ alone, who is “holy, blameless, unstained, separated from sinners” (Heb. 7:26).  Those who ignore and reject His righteousness “seeking to establish their own, are not under the righteousness of God” (Rom. 10:3).  Therefore the first use of this teaching lies in the article of justification, namely, that we not set before God’s judgment our imperfect and variously stained obedience to the Law but that we may learn that we are justified by faith in Christ.
• (2) The second use of this teaching lies in the article on good works, that we may learn that by the natural powers of our own free choice we cannot begin the sincere and true obedience we owe the Law, but the Law of God “must be written on our hearts” through the Holy Spirit (Jer. 31:33), so that we may begin to show not merely an external obedience but also an inner one with a spontaneous spirit and from the heart.  On the other hand, because this inchoate obedience is still very far from the perfection the Law requires, we cannot boast about it before the judgment of God but are forced to confess that “all our righteousnesses are as menstrual rags” (Isa. 64:6) and that, “when we have done everything, we are still but unworthy servants” (Luke 17:10).
• (3) Lastly, it serves to teach us that the inchoate obedience of the regenerate is pleasing to God, not because it satisfies the law perfectly but because it proceeds from faith in Christ; through such faith its imperfection and remaining fault is covered.

Johann Gerhard, On the Law