Dr. J. Gresham Machen, the renowned defender of biblical orthodoxy in early twentieth-century Presbyterianism, sent a telegram just before his death that read: “I’m so thankful for the active obedience of Christ. No hope without it.” Machen’s message indicates that we need both the death of Christ and His life of obedience to save us. It is not enough for our sins to be removed by the atonement; we also need a positive record of righteousness, obedience that fulfills the demands that God gave mankind to take dominion over the world for His glory (Gen. 1:26–28).
The recognition of our need for Christ’s active obedience to God goes back through the Protestant Reformation to the Apostles. As we see in today’s passage, Christ was born “under the law” to redeem those who are “under the law” (Gal. 4:4–5). But what does it mean to be under the law? In effect, it means to be obligated to keep the law perfectly in order to enjoy a right standing before God. By being born under the law, our Savior consented to fulfill its demands so that we can be released from its death sentence against those who do not obey it perfectly. John Calvin comments, “Christ chose to become liable to keep the law, that exemption from it might be obtained for us.”
We must be careful here. Paul is thinking primarily of the Mosaic law in Galatians 4:4–5, but we are not to understand the Mosaic covenant as a covenant of works given to sinners wherein they were expected to earn their righteousness before God. Remember that God gave the Mosaic law after redeeming His people. For sinners, grace precedes law, and seeking to be faithful to the law is how sinners thank God for His grace. Nevertheless, the law promises life to those who keep it perfectly (Lev. 18:5). Those who do it perfectly will be justified (Rom. 2:13). But sinners cannot keep the law with the perfection God demands, and recognizing this, God included in the law the gracious provision of sacrifices to atone for sin.
Yet none of this means that God could simply set aside His demands. In Adam we failed to please the Lord, and a just God cannot simply set His commands aside. His justice demands that His law be kept. In substance, the moral commands given to Adam are found in the Mosaic law, and by keeping these commands, our Savior did what we never could. By coming under the law and living a perfect life, He kept God’s demands on our behalf. His record of perfect law keeping is now ours by faith alone in Him (1 Cor. 1:30–31).