Romans 8:4

That the ordinance of the law might be fulfilled is us, who walk not after the flesh, but after the Spirit.

The great purpose of Christ's redemptive act was this, that people might keep all the law of God. The purpose of salvation in Christ, far from being that of mere imputation from without of a righteousness to mankind through such a device as the sinner's faith, was, on the other hand, concerned with the enabling of people to observe all of God's commandments in a true spirit of love and obedience, such becoming possible through the means here presented, that of walking after the Spirit and not after the flesh.

That the ordinance of the law might be fulfilled in us ... shows that God's purpose with reference to his commandments has been invariable from all eternity, and that God's purpose has not been diverted or diminished with regard to those who are called Christians. The manner of fulfilling God's commandments, however, has undergone a marvelous transformation in the new covenant. Whereas under the Old Testament regime, attention was directed to specific commandments of "thou shalt not" do this and "thou shalt" do that, under the New Testament system the believer in Christ lives a life of love and harmony with the Spirit of God. Paul earlier said that the law of Moses was spiritual (Romans 7:14), and, therefore, the law coincides absolutely in all of its commandments of moral uprightness with the Spirit of God. Thus, to walk in the Spirit is to fulfill the will of God.

Who walk not after the flesh ... This is an appropriate place to note Paul's use of the term "flesh." For three separate senses in which Paul employs this term, see under Romans 7:6. Paul did not teach that all flesh is by nature and from birth sinful. As Whiteside observed:

Human flesh is not sinful in and of itself; if so, the flesh of Jesus was sinful. ... Christ had in his nature all that the word "man" implies. "Since then the children are sharers in flesh and blood, he also in like manner partook of the same" (Hebrews 2:14). "Wherefore it behooved him in all things to be made like unto his brethren" (Hebrews 2:17). If Christ's brethren were born sinful and he was not, then he was not like them in all things. But as Jesus was made in all things like unto his brethren and was without sin, it shows conclusively that sin is not a part of man's nature. When Adam and Eve were created, they had all that belongs to human nature. Sin came into their lives as the result of a foreign element. Sin is no more a park of man's nature than is dust in the eye.[9]

The use of the word "likeness" in the preceding verse (which see) has led some to suppose that Christ partook of a human nature that was only similar to that of people, the dissimilarity being in that all other people possessed a sinful nature, and Christ did not. Such cannot be true because the author of Hebrews described Christ as one "tempted in all points like as we are, and yet without sin" (Hebrews 4:15). Now if Christ's very nature had been different from that of other people, it could not have been true that he was tempted as people are tempted. He would have had, in such a view, a variation that would have made that statement in Hebrews impossible. Therefore, as already noted, the sole reason for Paul's employment of the term "likeness" in the preceding verse was for the purpose of avoiding an implication that Christ's flesh was sinful, and not for the purpose of suggesting that his flesh was different from that of all people.

In the flesh ... as used here has reference to living in such a manner that the fleshly lusts, appetites and desires are the goals of life. That person who makes the satisfaction of temporal, bodily, social and animal instincts the end and all of living is walking after flesh. Thus Tertullian was correct:

It is the works of the flesh, not the substance of the flesh, which St. Paul condemns. ... The apostle everywhere condemns the works of the flesh in such a way as to appear to condemn the flesh; but no one can suppose him to have any such view.[10]

[9] Robertson L. Whiteside, A New Commentary on the Epistle of Paul to Saints in Rome (Denton, Texas: Miss Inys Whiteside, 1945), p. 170.

[10] Tertullian, The Ante-Nicene Fathers (Grand Rapids, Michigan: Wm. B. Eerdmans Publishing Company, 1957), Vol. III, 578-579.