Romans 8: 3 – 4
But what law could not do, God did by sending his very own Son with a nature that resembled our sinful nature. He came in the “likeness of sinful man.” If Christ had not taken on our nature, he could not have been one of us. On the other hand, had he become completely like us (i.e., had he sinned), he could not have become our Savior. Barrett translates “in the form of flesh which had passed under sin’s rule,” which means that “Christ took precisely the same fallen nature that we ourselves have, and that he remained sinless because he constantly overcame a proclivity to sin.” His mission was to put an end to sin, to condemn that evil power that has, since the dawn of history, held the human race in bondage. Knox says that God “signed the death warrant of sin.” In a related passage the author of Hebrews wrote that Jesus “shared in [the] humanity” of his brothers so as to “destroy him who holds the power of death—that is, the devil” and to “free those who all their lives were held in slavery by their fear of death” (Heb 2:14–15). But not only did Christ come “in appearance as a man” (Phil 2:8) but also that he might be “a sin offering.” Similarly, Hebrews says that he became a “merciful and faithful high priest … that he might make atonement for the sins of the people” (Heb 2:17). Although the NIV translates, “So he condemned sin in sinful man” [italics added], it is better to take the literal translation (“in the flesh”) as a reference to Christ’s human nature, not ours. That is where God condemned sin. It was in the person of the incarnate Son that the Father brought an end to the power of sin.
God’s redemptive action in Christ was so that what the law justly demanded of us might be fully satisfied. This righteous requirement is met “in us” not in the sense that we fulfilled its demands but rather that God met it through the sacrificial death of his Son. The just requirement (singular in Greek, stressing the unity of OT law) of the law is summarized in 13:9 as “Love your neighbor as yourself.” And who are we? We are those whose lives were once under the control of a sinful lower nature but now are guided and empowered by the Spirit of God. W. H. G. Thomas illustrates the principle of living “according to the Spirit” by comparing the motor car that operates on the storage principle and the tram that runs on the contact principle. “It is the latter that God has adopted for holiness.” We do not store up grace but stay in constant contact with the one who is the source of all life and power. Our lives display the “fruit of the Spirit” (Gal 5:22–23). This kind of life demonstrates that the righteous requirements of the law have been met in us.
Mounce, R. H. (1995). Romans (Vol. 27, pp. 175–177). Nashville: Broadman & Holman Publishers.