Romans 8:3

For what the law could not do, in that it was weak through the flesh, God, sending his own Son in the likeness of sinful flesh and for sin, condemned sin in the flesh.

The law of Moses could not make people perfect, due to the weakness of people themselves in being unable to live according to its tenets. There were also certain other limitations in that ancient divine law, there having been no provision for the impartation of God's Spirit to help people, and no absolute forgiveness, there having been a remembrance of sin made again every year, even after observance of the ceremonies which typically "removed" them. (See under Romans 10:2 in my Commentary on Hebrews.) The law could not extend justification to people except upon the premise of perfect obedience, and the weakness of all flesh prevented such a thing from ever occurring.

God sending his own Son ... Jesus came into the world to achieve perfection as a man and upon man's behalf. He came to fulfill the whole will of God, to obey God's every word of commandment, and to "fulfill all righteousness." Christ's faith was perfect; his obedience was perfect; his love of the Father was perfect; he was totally perfect. In Christ, therefore, is the righteousness which alone can save people; and, as to the manner of this righteousness being made available for the salvation of sinners, see under Romans 8:1. As David Lipscomb wrote:

Jesus Christ came as the perfect embodiment of obedience to the law of God, and with the purpose of inspiring others with the same spirit and leading all who trust in him to the same obedience from the heart to the law of God.[6]

In the likeness of sinful flesh ... Here is a precise distinction. The apostle did not declare that Jesus came "in" the sinful flesh, but "in the likeness" of it, the significance of this lying in the fact that our Lord's flesh was not sinful, but only like the flesh of sinful people, their flesh being sinful, not from birth, but through the practice of sin.

Perhaps people may never know why it was so absolutely necessary that God should become a man in the person of Christ, down to the very last details of conception and birth, and with all the normal attributes and characteristics of people, even to the suffering of weariness, pain, and death; but the fact of that necessity is apparent, not merely in the act of incarnation itself, but in all of the typical and prophetic representations of it, as for example when Moses lifted up the brazen serpent in the wilderness, the healing serpent being "like" poisonous ones (Numbers 21:8)! But why did Paul use such an expression as "the likeness of sinful flesh," an expression found nowhere else in the word of God? True, Paul used such expressions as "made of the seed of David according to the flesh" (Romans 1:3), "manifested in the flesh" (1 Timothy 3:16), and "made in the likeness of men" (Philippians 2:7); but the use of such an expression here must have fulfilled some special purpose. Murray's exegesis provides a plausible explanation, thus:

He is using the term "likeness" not for the purpose of suggesting any unreality in respect of our Lord's human nature. That would contradict Paul's express language elsewhere in this epistle and in his other epistles. He is under the necessity of using this word here because he uses the term "sinful flesh"; and he could net have said that Christ was sent in "sinful flesh." That would have contradicted the sinlessness of Jesus for which the New Testament is jealous throughout. So the question is, Why did Paul use the term sinful flesh, when it is necessary to guard so jealously the sinlessness of our Lord's flesh? He is concerned to show that when the Father sent the Son into this world of sin, of misery, and of death, he sent him in the manner that brought him into closest relation to sinful humanity that it was possible for him to have without becoming sinful himself. He himself was holy and undefiled - the word "likeness" guards this truth. But he came in the same human nature; and that is the purpose of saying "sinful flesh." No other combination of terms could have fulfilled these purposes so perfectly.[7]

Let it be noted, however, that the flesh of humanity is sinful, not from birth or by nature, but from the practice of sin.

And for sin ... is Paul's way of stating the purpose of Christ's coming into the world. It was on account of sin, to deal with sin, to provide an atonement for sin, to condemn sin in the flesh, as stated a moment later.

Condemn sin in the flesh ... does not mean to condemn the people who sinned, the law of Moses having been far more than sufficient for such a purpose as that, but to condemn sin in the sense of taking away its dominion over people, stripping sin of its power to hold the entire race of man captive in sin. This expression reminds one of Paul's saying that Jesus "led captivity captive and gave gifts unto men" (Ephesians 4:8). Here the meaning is that Christ condemned the condemnation due to sin, and sin, almost personified, is said to be itself condemned. The law of God to the effect that sin deserved the penalty of death could not be thrust aside and merely ignored; the penalty had to be executed; and, in the weakness and sinfulness of humanity, there appeared to be no hope whatever that this penalty could be removed by the actual living of a pure and holy life. Thus, it was necessary that if the penalty should be enforced and at the same time humanity spared, it was mandatory that the Holy One should descend from above and pay it himself upon their behalf. That is what Jesus did! To provide such a great gift on behalf of man was the purpose of Christ's coming into this world. As Brunner commented:

God's Son had to assume the sinful flesh (the likeness of it) in order to be able to bear and take away its burden. Godhood and manhood had to be in an incomprehensible manner united in it so that God's law could really be fulfilled.[8]

[6] David Lipscomb, A Commentary on the New Testament Epistles (Nashville, Tennessee: The Gospel Advocate Company, 1969), p. 143.

[7] John Murray, op. cit., I, p. 280.

[8] Emil Brunner, op. cit., p. 68.